What this TDEE calculator does
TDEE — total daily energy expenditure — is the number of calories your body burns in a day, factoring in both your resting metabolism and physical activity. This English-language TDEE calorie calculator uses the Mifflin-St Jeor equation, the most widely validated formula for estimating BMR in non-athletic adults, and then applies an activity multiplier to produce your maintenance calories. From there it shows cut and bulk targets at −20%, −10%, +10%, and +20%, plus a suggested 30P/40C/30F macro split at maintenance. One important caveat worth keeping front-of-mind: these equations carry a real-world error range of ±10–15%. The CDC BMI resource notes that single-metric body estimates are screening tools, not clinical diagnoses — the same logic applies here. Treat your TDEE as a starting point, then adjust based on your actual two-week weight trend. 100% client-side — your data never leaves your browser. No uploads, no tracking, no server logs.
Features
- Mifflin-St Jeor BMR. Calculates your basal metabolic rate using the most widely cited equation for general adult populations, factoring in sex, age, height, and weight.
- Five activity levels. From sedentary desk work to a physical job or twice-daily training — each multiplier maps to a distinct lifestyle pattern so your TDEE estimate reflects real output.
- Cut and bulk targets. Shows four calorie targets alongside maintenance: a light cut (−10%), aggressive cut (−20%), light bulk (+10%), and standard bulk (+20%) — covering the full range of common goals.
- Macro breakdown. Breaks maintenance calories into grams of protein, carbohydrates, and fat using a 30/40/30 split — a reasonable starting point before you dial in your own ratios with the [Macro Calculator](/en/macro-calculator/).
- Metric and imperial inputs. Switch between kilograms/centimeters and pounds/inches without re-entering your data. All conversions happen instantly in the browser.
- Honest accuracy warnings. The calculator surfaces the known limits of activity multipliers and adaptive thermogenesis so you calibrate against your real trend rather than over-trusting a single output.
How to use the TDEE calculator
Enter your stats, pick your activity level, and read off your maintenance calories and targets. The whole calculation runs locally — no form submission required.
- Choose your unit system. Select Metric (kg, cm) or Imperial (lb, in) at the top. The input fields update immediately.
- Enter your stats. Fill in sex, age, weight, and height. These four values drive the Mifflin-St Jeor BMR formula: for males, BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5.
- Pick your activity level. Choose the option that best matches your typical week. If you have a desk job but lift four days a week, 'Moderate (3-5×/week)' is usually the right fit — avoid over-selecting 'Active' to compensate for a hard session or two.
- Read your results. The panel shows BMR, TDEE (maintenance), four calorie targets, and macro grams. Use the maintenance figure as your baseline calorie budget, then track your weight over two weeks before adjusting.
- Cross-check with body composition. Mifflin-St Jeor estimates lean-mass implicitly from total weight. If you're carrying significant muscle mass, your actual BMR may run higher. Pair this result with a [BMI calculator](/en/bmi-calculator/) check to flag any large variance.
Common use cases
- Starting a 4-week cut. Use the −10% light-cut target to set a moderate deficit. Aggressive 20% deficits work short-term but accelerate muscle loss and trigger adaptive thermogenesis — the metabolic slowdown that makes prolonged dieting harder than the math suggests.
- Planning a lean bulk. The +10% target adds roughly 200–350 kcal above maintenance for most adults — enough to support muscle gain while limiting fat accumulation. Many intermediate lifters in places like Toronto or London use this range through a 12-week hypertrophy block.
- Comparing activity scenarios. Run the calculator twice — once for your current sedentary stretch, once for your planned training block — to see how much the activity multiplier shifts your maintenance. The gap is often smaller than people expect, which is why out-running a poor diet rarely works at moderate training volumes.
- Client education in fitness coaching. Show clients why a 500 kcal/day crash diet undershoots their actual TDEE calorie deficit needs and risks muscle catabolism. A concrete number makes the conversation less abstract than generalized advice about 'eating less.'
- Macro baseline before fine-tuning. The 30P/40C/30F split gives a defensible starting point before adjusting protein up for a cut or carbohydrates up for endurance athletes. It pairs naturally with detailed tracking in a logging app once you have your calorie ceiling set.
Frequently asked questions
What does TDEE mean?
TDEE stands for Total Daily Energy Expenditure — the total calories your body uses in a day, including your resting metabolism (BMR) plus the energy burned through movement, digestion, and deliberate exercise.
How accurate is a TDEE calculator?
Equation-based estimates carry a ±10–15% error range for most people. Activity multipliers were derived from population studies, not individual measurements, so a desk worker who lifts five days a week often sits between two categories. The most reliable approach is to use the calculator for an initial estimate, then track your weight daily for two weeks and adjust calories based on the actual trend. Daily calorie counts are noisy by ±200 kcal or more; the two-week average smooths that variance.
Why might my real TDEE be lower than the calculator shows — especially if I'm obese?
People with obesity sometimes have lower-than-predicted TDEEs because the Mifflin-St Jeor formula uses total body weight, which includes fat mass that burns fewer calories at rest than lean tissue does. Additionally, prolonged caloric restriction triggers adaptive thermogenesis, which reduces TDEE beyond what the equations predict. If your weight isn't changing at the calculated deficit, recalculate based on your current weight and lower the target by 5–10%.
What's the difference between BMR and TDEE?
BMR (basal metabolic rate) is the calories your body needs at complete rest — think of it as the energy cost of simply existing. TDEE multiplies BMR by an activity factor to account for everything you do during the day. For most sedentary adults, TDEE runs about 1.2× BMR; for very active individuals it can reach 1.9× or higher.
Is my data saved or sent to a server?
No. This calculator runs entirely in your browser using client-side JavaScript. Nothing you enter — weight, age, sex, or activity level — is transmitted to any server, stored in a database, or logged. You can verify this by running it offline: the results are identical. This is the same privacy model described in web standards like those documented on MDN Web Docs for client-side APIs.
Should I use Mifflin-St Jeor or a different formula?
Mifflin-St Jeor is the most validated option for the general adult population and is the default in most clinical and fitness contexts. If you have an unusually low body-fat percentage — competitive bodybuilders or endurance athletes — the Katch-McArdle formula, which takes lean body mass as input, tends to be more accurate because it strips out the fat mass that skews Mifflin estimates upward. For most people who aren't tracking lean mass separately, Mifflin-St Jeor is the practical choice.