2026-05-13 · nutrition, calorie-deficit, tdee, beginner · 22 min read

Updated 2026-05-20

How do I calculate my TDEE as a beginner?

Use the Mifflin-St Jeor equation to estimate BMR from your weight, height, age, and sex, then multiply by an activity factor (1.2 sedentary up to 1.55 moderately active). For a quick shortcut, multiply your body weight in pounds by 14 to 16 kcal. Treat the result as a starting point and adjust after two to four weeks of weight trend data.

What is the safest calorie deficit for beginners?

For most beginners, a deficit of 300 to 500 kcal per day below TDEE is the safest starting range. It supports about 0.5 to 1 lb (0.25 to 0.45 kg) of weight loss per week, protects muscle when paired with adequate protein, and stays manageable without extreme hunger. Avoid going below roughly 1,200 kcal (women) or 1,500 kcal (men) without clinician input.

Is a 500-calorie deficit too much?

For most healthy adults at or above a normal body weight, a 500 kcal daily deficit is not too much and targets about 1 lb of weight loss per week. It can be too aggressive for smaller adults, anyone already eating near 1,500 kcal, or people with high training demands. If a 500 kcal cut drops you below safe minimum intakes, scale back to 250 to 300 kcal.

How accurate are TDEE calculators?

Calculators that use the Mifflin-St Jeor equation are the most accurate of the common formulas, but they still carry about a 10 to 20 percent margin of error. Use them as a starting point, then let two to four weeks of real weight trend data tell you if you need to adjust.

Should I eat back the calories I burn during exercise?

For most beginners, no. Fitness trackers and cardio machines often overestimate calorie burn by 20 to 50 percent. A simpler approach is to pick an activity multiplier that already reflects your normal training, then leave your daily calorie target fixed.

What is a safe minimum calorie intake?

General clinical guidance suggests roughly 1,200 kcal per day for women and 1,500 kcal per day for men as a floor when dieting without medical supervision. Going below those numbers on your own increases the risk of nutrient deficiencies, muscle loss, and binge-restrict cycles.

Is 1,200 calories a day enough?

For many adult women, 1,200 kcal is at the low end of the safe range and is hard to meet protein and nutrient needs on. Unless a clinician has set that number for you, a modest deficit from your estimated TDEE is usually more sustainable and better for muscle preservation.

Do I need to track calories forever?

No. Many people track closely for 4 to 12 weeks to calibrate portion sizes, then shift to simpler approaches like protein targets, plate composition, or occasional check-ins. Learning what your usual meals contain is the real skill, not the tracking itself.

How do I calculate my TDEE without a calculator?

A rough shortcut many clinicians use is 14 to 16 kcal per pound of body weight for maintenance, depending on activity. A sedentary 180 lb adult would land around 2,520 to 2,880 kcal. It is less precise than Mifflin-St Jeor but close enough to start with. Run the math by hand once a month and adjust based on two to four weeks of weight trend data.

What is a beginner calorie deficit?

A beginner calorie deficit is eating about 300 to 500 kcal per day below your TDEE. That gap drives roughly 0.5 to 1 lb (0.25 to 0.45 kg) of weight loss per week while leaving room for protein, satiety, and a normal social life. Most adults can hold this range for weeks without extreme hunger or rebound eating, which is why it outperforms aggressive crash diets over the long run.

How many calories below TDEE should I eat?

For most beginners, 300 to 500 kcal below TDEE per day is the sweet spot. It is gentle enough to sustain for 8 to 12 weeks but steep enough to lose about 0.5 to 1 lb per week. Smaller adults, or anyone already eating near 1,500 kcal, should start at 250 to 300 kcal. Never drop below roughly 1,200 kcal (women) or 1,500 kcal (men) without clinician input. If hunger spikes or energy crashes, ease back.

TDEE and Calorie Deficit: A Beginner’s Guide With Examples

Your TDEE is the total calories you burn in a day, and a beginner-friendly calorie deficit is 300 to 500 calories below that number. To estimate TDEE in plain English, multiply your bodyweight in pounds by 14 to 16 (lower if you sit most of the day, higher if you train hard), or run the Mifflin-St Jeor equation using your weight, height, age, and sex for a more precise number. Most adults eating in that 300 to 500 kcal deficit range lose about 0.5 to 1 lb (0.25 to 0.45 kg) per week without crash dieting or extreme hunger.

Quick reference: 1 stone = 14 pounds (about 6.35 kg). So a 12 st 4 lb starting weight is 172 lb (about 78 kg) for the Mifflin-St Jeor equation. UK readers can pick “Stones & pounds” in the calculator above and skip the conversion.

Calorie deficit by body weight (quick reference)

Maintenance numbers use the 14 kcal/lb (sedentary) and 15 kcal/lb (lightly active) clinical shortcut. The deficit column subtracts roughly 375 kcal/day to target about 0.75 lb (0.34 kg) per week of weight loss. Adults already eating near 1,500 kcal, or anyone whose target falls below the 1,200 kcal women’s / 1,500 kcal men’s floor, should use a smaller 250 to 300 kcal deficit instead. For sex-specific guidance, our men’s calorie targets guide breaks down maintenance and deficit numbers by weight and activity level, and weight loss for women over 40 covers the recalculation that often becomes necessary during perimenopause.

If you are new to weight loss, almost every plan eventually points back to the same question: how many calories should you eat? The short answer is “fewer than your body burns.” The more useful answer involves two numbers called BMR and TDEE, a simple equation, and a modest deficit you can actually hold. This guide walks through the basics in plain English so you can estimate a reasonable target without extreme diets or complicated math. Looking for more tools? See all four free weight-loss calculators in one place.

Who this is for / not for

Good fit if:

• You are new to calorie tracking and want to understand where the numbers come from.
• You have been told to “eat in a deficit” and want to know how to set one safely.
• You want an evidence-based starting point before trying a stricter plan or medication.
• You have checked your BMI calculator result and want to turn “I should lose some weight” into an actual daily calorie target.

Not a fit if:

• You are pregnant, breastfeeding, recovering from an eating disorder, or medically managed on a specialized diet. Your targets should be set by your care team.
• You are an elite athlete trying to optimize performance nutrition. Your needs are more specific than a general calculator can handle.
• You are looking for a very low calorie or crash diet plan. This article focuses on moderate, sustainable deficits.

What is TDEE?

TDEE stands for total daily energy expenditure. It is the total number of calories your body burns in a typical 24 hour day. TDEE has four parts:

• Basal metabolic rate (BMR). The calories your body uses at rest just to keep you alive (heart, brain, breathing, temperature, organ function). For most adults, BMR accounts for roughly 60 to 70 percent of TDEE.
• Physical activity. Structured exercise like walks, workouts, or sports.
• Thermic effect of food (TEF). The calories your body uses to digest and process what you eat, usually about 10 percent of intake.
• Non-exercise activity thermogenesis (NEAT). Everything else you do, like standing, fidgeting, commuting, cleaning, and moving around the house.

When people say “eat at your TDEE,” they mean eating the number of calories your body uses each day. If you eat less than that over time, you lose weight. If you eat more, you gain.

BMR vs TDEE

BMR and TDEE are often confused, but they measure different things.

• BMR is the minimum number of calories your body would burn if you stayed in bed all day, fully rested, not digesting food.
• TDEE is your BMR plus the calories you burn from movement, digestion, and daily activity.

For weight loss math, TDEE is the number that matters, because it reflects your real world calorie burn. BMR is the building block used to estimate it.

How to estimate your TDEE

The most widely used equation for BMR is the Mifflin-St Jeor equation. It is considered the most accurate of the common predictive equations for healthy adults.

Mifflin-St Jeor (in metric):

• Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5
• Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161

Once you have BMR, multiply by an activity multiplier to estimate TDEE. The table below shows the five standard multipliers with a real-world example so you can pick the one that honestly matches your week.

If you are between rows, round down rather than up — most adults overestimate their activity level by about half a category, which inflates TDEE and shrinks the real deficit.

Worked example: 35-year-old woman, 5’6”, 165 lb, desk job

Let’s walk one full calculation end to end — BMR through to a daily calorie target — so the steps are concrete.

Convert to metric first:

• 165 lb ÷ 2.205 ≈ 75 kg
• 5’6” = 66 in × 2.54 ≈ 168 cm

Step 1 — BMR (Mifflin-St Jeor for women):

BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161

BMR = (10 × 75) + (6.25 × 168) − (5 × 35) − 161

BMR = 750 + 1,050 − 175 − 161

BMR ≈ 1,464 kcal/day

Step 2 — Pick an activity multiplier. A desk job with little or no formal exercise is sedentary = 1.2 (see the activity table above).

Step 3 — TDEE:

TDEE = BMR × multiplier

TDEE = 1,464 × 1.2

TDEE ≈ 1,757 kcal/day

Step 4 — Choose a deficit. Beginner range is 300 to 500 kcal/day. We’ll use 400 kcal as a middle-of-the-road starting cut.

Step 5 — Daily calorie target:

Daily target = TDEE − deficit

1,757 − 400 = about 1,360 kcal/day

This target sits above the 1,200 kcal women’s floor and projects roughly 0.8 lb (0.36 kg) of weight loss per week. If hunger feels extreme in week one, ease the deficit to 300 kcal (about 1,460 kcal/day). If the scale is flat after three weeks of honest tracking, deepen to a 500 kcal deficit (about 1,260 kcal/day) before cutting any further.

Important: these formulas give estimates, not exact readings. Real metabolic rate can vary by 10 to 20 percent between two people with the same height, weight, age, and activity level. Treat the number as a starting point, not a verdict. Many free online TDEE calculators use this same equation. They are a reasonable starting place, but they are not more accurate than doing the math yourself.

For more detail on how to eat inside the number you land on, see our guide to structured calorie restriction. For practical calorie ranges based on your body size and activity level, see how many calories to eat each day. If you would rather start from a structured eating template than build menus from scratch, our weight loss meal plan gives a 7-day framework you can adjust to your calorie target.

What is a calorie deficit?

A calorie deficit is when you eat fewer calories than your TDEE over time. That gap forces your body to make up the difference from stored energy, which is mostly body fat (with some lean tissue if protein is too low). The bigger the daily gap, the faster the weight loss, but the harder the diet is to sustain. Most beginners do best with a moderate deficit of 300 to 500 kcal per day below TDEE, paired with adequate protein and a small amount of daily activity.

A useful mental model: a deficit of about 3,500 kcal equals roughly 1 lb (0.45 kg) of fat loss. So a 500 kcal daily deficit averages out to about 1 lb per week, while a 250 kcal deficit averages about 0.5 lb per week. Real-world results vary because water weight, glycogen, and tracking accuracy all affect the scale, but the directional math holds over multi-week stretches. If you cannot or do not want to train, the deficit can still be created from food alone — see our walkthrough of diet-only weight loss for the realistic plan and trade-offs.

Quick reference: TDEE and deficit by body weight

The table below uses the 14 to 16 kcal per lb clinical shortcut to estimate maintenance calories at common anchor weights, then subtracts a 500 kcal target deficit. Use it as a sanity check before building a more precise plan with the Mifflin-St Jeor equation. If a 500 kcal cut would drop you below the safe minimum (1,200 kcal women, 1,500 kcal men), use a smaller 250 to 300 kcal deficit instead.

If your maintenance number lands lower than these ranges (common for shorter or older adults), see why your TDEE may be low and how to raise your TDEE through movement and training before cutting calories deeper.

Picking a safe deficit

Once you have a TDEE estimate, a calorie deficit is simply eating fewer calories than that number.

Two common, evidence-based approaches:

• Percentage based. Subtract roughly 10 to 25 percent from your TDEE. A 10 to 15 percent deficit is gentle and sustainable. A 20 to 25 percent deficit is more aggressive and typically short term.
• Fixed number. Subtract about 500 kcal per day from your TDEE to target roughly 1 lb (0.45 kg) of weight loss per week. A 250 kcal deficit is gentler and targets about 0.5 lb per week. For specific timelines at different deficit sizes, see our guide on how long it takes to lose weight — or jump straight to its weight loss timeline calculator to project a target date from your current and goal weight.

NIH and NHLBI clinical guidelines on overweight and obesity support modest deficits of roughly 500 to 750 kcal per day for most adults seeking weight loss, combined with physical activity and behavioral support. The guidelines also note general “safe minimum” intakes of about 1,200 kcal per day for women and 1,500 kcal per day for men when dieting without medical supervision. Going below these floors on your own raises the risk of nutrient deficiencies and muscle loss.

A few practical rules:

• Keep protein up. Aim for a protein anchor at each meal and lean on high-protein snacks between meals to hit your daily total without blowing through your calorie budget. See protein intake for weight loss for gram-per-kilogram targets.
• Fight hunger with volume. Build meals around filling low-calorie foods like vegetables, broth-based soups, and high-water fruit so a deficit feels less restrictive.
• Do not cut deeper than you need. A smaller deficit you can hold beats a big one you cannot.
• Pair with activity. Even a modest walking routine makes the deficit easier to create without cutting food as hard. See exercise for weight loss.

Common mistakes beginners make

• Cutting calories too deep. Jumping straight to 1,000 or 1,100 kcal often backfires through extreme hunger, low energy, and rebound eating.
• Ignoring protein. In a deficit, protein protects muscle. Skipping it means more of the weight you lose comes from lean tissue.
• Guessing portion sizes. Oils, nut butters, rice, and cheese are easy to underestimate. A kitchen scale for the first week or two calibrates your eye — our guide to how to count calories walks through the practical weigh-log-label workflow most beginners need.
• Not recalculating after losing weight. A smaller body burns fewer calories. Update your TDEE every 10 to 15 lb (5 to 7 kg) of loss. If your maintenance calories are unusually low after the recalculation, raise daily activity before cutting food further — a steeper cut from an already-thin TDEE is usually counterproductive.
• Treating calculators as gospel. TDEE calculators are estimates. Adjust based on two to four weeks of real data, not what the number “should” be.
• Forgetting liquid calories. Juice, coffee drinks, smoothies, and alcohol add up quickly and are often untracked.
• Skipping weekends. A clean Monday through Thursday can be undone by three loose days. Weekly totals are what matter.

How to adjust over time

TDEE is not fixed. It changes as your body weight, activity, and training change. Here is a simple adjustment routine:

1. Set a starting target using the Mifflin-St Jeor equation and a modest deficit (10 to 20 percent under TDEE).
2. Track your average weekly weight using a 7-day rolling average rather than a single daily number.
3. Review every 2 to 4 weeks. If the average weekly weight is dropping 0.5 to 1 percent of body weight per week, stay the course. If it is flat for 3 or more weeks, something needs to change.
4. Make small adjustments. Trim 100 to 200 kcal per day, or add the same as activity, before cutting further.
5. Rebuild when you hit your goal. Shift to a maintenance intake at your new TDEE and give your body time to adapt before any future cuts.

If progress stalls for several weeks despite honest tracking, review the troubleshooting steps in our weight loss plateau guide before cutting calories deeper. After 8 to 12 weeks of continuous deficit, a structured refeed or short maintenance break can also reset hunger and adherence before the next cut — the side-by-side guide covers when each tool is the right call.

What to do if your TDEE feels low

Some people run the math and land on a TDEE of 1,500 to 1,700 calories, which leaves very little room for a deficit without eating uncomfortably little. This is especially common for shorter adults, people with desk jobs, and anyone who has already lost a significant amount of weight. A low TDEE is not a sign that your metabolism is broken. It is usually driven by body size, daily movement levels, or a history of aggressive dieting that has reduced non-exercise activity.

If your estimated TDEE feels uncomfortably low, raising your daily activity is usually more productive than cutting food further. Adding a daily walk, standing more throughout the day, and incorporating two to three strength training sessions per week can shift your activity multiplier and increase your TDEE by 100 to 300 calories. Protecting protein intake also helps, since protein has the highest thermic effect of any macronutrient and supports lean mass during a deficit.

For a full breakdown of why TDEE can be lower than expected, what does and does not explain it, and practical strategies to raise your daily burn, see our guide to low TDEE.

Frequently asked questions

How accurate are TDEE calculators? Calculators that use the Mifflin-St Jeor equation are the most accurate of the common formulas, but they still carry about a 10 to 20 percent margin of error. Use them as a starting point, then let two to four weeks of real weight trend data tell you if you need to adjust.

Should I eat back the calories I burn during exercise? For most beginners, no. Fitness trackers and cardio machines often overestimate calorie burn by 20 to 50 percent. A simpler approach is to pick an activity multiplier that already reflects your normal training, then leave your daily calorie target fixed.

What is a safe minimum calorie intake? General clinical guidance suggests roughly 1,200 kcal per day for women and 1,500 kcal per day for men as a floor when dieting without medical supervision. Going below those numbers on your own increases the risk of nutrient deficiencies, muscle loss, and binge-restrict cycles. Medically supervised very low calorie diets can be appropriate for some patients but should not be self-prescribed.

Is 1,200 calories a day enough? For many adult women, 1,200 kcal is at the low end of the safe range and is hard to meet protein and nutrient needs on. Unless a clinician has set that number for you, a modest deficit from your estimated TDEE (for example, 300 to 500 kcal below TDEE) is usually more sustainable and better for muscle preservation.

Do I need to track calories forever? No. Many people track closely for 4 to 12 weeks to calibrate portion sizes, then shift to simpler approaches like protein targets, plate composition (half vegetables, a palm of protein, a portion of starch), or occasional check-ins. Learning what your usual meals contain is the real skill, not the tracking itself. If you want to compare common eating patterns once you have a starting target, see our roundup of the best diet for weight loss.

What if I have a slow metabolism? Measured BMR varies by only about 10 to 15 percent between most people of similar size, sex, and age. True clinically “slow” metabolism is rare and usually linked to a thyroid or hormonal condition that a clinician can evaluate. More often, apparent slowness reflects underreporting of food intake or less daily movement than expected. If your calculated TDEE is genuinely low due to smaller body size or limited movement, see our guide on working with a low TDEE for practical strategies.

What if my TDEE is low? A low TDEE usually is not a sign that something is broken. It is a result of the math, and three factors tend to drive it down:

1. Smaller body size. BMR scales with weight, so a 130 lb person simply burns fewer calories at rest than a 200 lb person. As you lose weight, your TDEE drops with it.
2. Low daily movement. If you work at a desk and do not exercise regularly, your activity multiplier stays near 1.2, which keeps TDEE close to BMR. Even modest additions like a daily walk or standing more during the day can shift that multiplier and raise your total burn by 100 to 300 kcal.
3. Aggressive dieting. Large calorie cuts can reduce non-exercise activity (NEAT) without you noticing. You fidget less, move slower, and take fewer spontaneous steps. This quietly lowers your real TDEE below what the calculator predicted.

If your estimated TDEE feels uncomfortably low, focus on protecting movement rather than cutting food further. Adding activity raises the burn side of the equation without requiring you to eat less. See our low TDEE guide for a deeper look at what drives a low number and how to work with it. If weight loss has stalled despite a genuine deficit, review the troubleshooting steps in our weight loss plateau guide.

Can I calculate TDEE without a calculator? A rough shortcut many clinicians use is 14 to 16 kcal per pound of body weight for maintenance, depending on activity. A sedentary 180 lb adult would land around 2,520 to 2,880 kcal. It is less precise than Mifflin-St Jeor but close enough to get started.

Practical next steps

This week

• Calculate your BMR with Mifflin-St Jeor and pick an activity multiplier that honestly matches your current routine.
• Set a starting deficit at 10 to 20 percent below TDEE, never below the 1,200 kcal (women) or 1,500 kcal (men) general floor without clinician input.
• Turn that target into a weekly menu using our step-by-step meal plan walkthrough.
• Hit a protein target and add a 10 to 20 minute walk most days.

What to track

• Weekly average weight (7-day rolling average).
• Daily calories, at least for the first 2 to 4 weeks.
• Protein grams per day.
• Steps or active minutes.

How to know it is working

• Average weekly weight trends down 0.5 to 1 percent of body weight per week.
• Hunger is manageable, not extreme.
• Energy for daily life and training stays steady.

How this article was researched

We reviewed peer-reviewed research on predictive equations for resting metabolic rate, energy balance, and calorie deficits in adults, along with public clinical guidance from NHLBI on the evaluation and treatment of overweight and obesity. Numbers used in this article (Mifflin-St Jeor coefficients, activity multipliers, and deficit ranges) are drawn from the cited sources rather than general rules of thumb. Safe minimum intakes reflect widely cited clinical guidance and are framed as starting thresholds, not individualized medical advice.