TL;DR
- The best free TDEE and calorie calculator is whichever one shows its math and never asks for a card. Our TDEE Calculator and BMR Calculator are free, account-free, and built on the same Mifflin-St Jeor equation dietitians use; the Calorie Deficit Calculator then turns that number into a daily target and timeline.
- Most "calorie calculators" inside apps are really food loggers with a one-time setup wizard. MyFitnessPal does not give you a TDEE; it returns a daily calorie goal from a Mifflin-St Jeor BMR times an activity bucket you pick, and expects you to log exercise separately.[3]
- The formula underneath is accurate to within 10% of measured resting metabolism for roughly 70-82% of people, which makes it a good starting hypothesis and a poor precise number for any one person.[2]
- What you should pay for is logging, not the calorie estimate. Barcode scanning and custom macro goals are Premium-gated in MyFitnessPal; the calorie goal itself is free, and a free calculator gives you the same starting number without the upsell.[4]
Search "free calorie calculator" and you land on a wall of apps that want an email, a credit card on file after a trial, or an upsell to Premium before they tell you a number. The honest truth is that the calorie estimate every one of them sells is the same textbook equation, and you can get it for free with no account. This roundup recommends the free tools worth using, explains exactly what they compute, and compares them honestly against the named apps people usually reach for. Every accuracy claim below is sourced to published research, not an in-house test.
What a "TDEE calculator" actually does
Almost every TDEE and calorie tool runs the same two-step calculation. First it estimates your basal metabolic rate (BMR) — the energy you burn at rest — from your sex, age, height, and weight using the Mifflin-St Jeor equation, the formula most dietitians prefer because it generalises better than the older Harris-Benedict.[1] Then it multiplies that BMR by an activity factor tied to a lifestyle bucket you choose, producing your total daily energy expenditure (TDEE). MyFitnessPal's goal wizard does exactly this, then subtracts your chosen weekly deficit to set a daily calorie goal.[3] Our breakdown of whether MyFitnessPal's TDEE is accurate walks through the same machinery in detail.
Because the math is shared, no calculator is meaningfully "more accurate" than another at this step — they differ only in whether they show the equation, whether they charge for it, and how they help you act on the result. Frankenfield and colleagues tested the major resting-metabolic-rate equations against indirect calorimetry and found Mifflin-St Jeor landed within 10% of measured values for about 70-82% of people depending on body size.[2] That is the ceiling on any free or paid calculator: a solid starting hypothesis, never a precise per-person number.
The free tools we recommend
| Tool | Inputs | Outputs | Cost |
|---|---|---|---|
| BMR Calculator | Sex, age, weight, height, activity level | BMR (Mifflin-St Jeor), maintenance calories, fat-loss and lean-gain targets, protein baseline | Free, no account |
| TDEE Calculator | Sex, age, weight, height, activity | Total daily energy expenditure for maintenance | Free, no account |
| Calorie Deficit Calculator | TDEE, current weight, target weight, timeline (weeks) | Daily deficit, target intake, deficit as % of TDEE, projected week-by-week timeline | Free, no account |
The BMR Calculator takes your sex, age, weight, height, and activity level and returns your Mifflin-St Jeor BMR, your scaled maintenance calories, fat-loss (maintenance minus 500) and lean-gain (maintenance plus 250) targets, and a protein baseline at 1.8 g/kg. That is the same starting number a MyFitnessPal setup wizard produces, shown with its working instead of hidden behind a goal screen.
Where the free path pulls ahead is acting on the number. The Calorie Deficit Calculator takes your TDEE, current weight, target weight, and a timeline in weeks, and returns the daily deficit required, your target daily intake, that deficit expressed as a percentage of TDEE, and a week-by-week projected bodyweight trend. It also flags a plan as aggressive once the deficit exceeds 25% of TDEE — the band where metabolic adaptation accelerates and lean-mass loss tends to climb. That is real coaching guidance most free app wizards do not give you, and it costs nothing.
Honest comparison with the named apps
The apps are not bad; they are just solving a different problem. MyFitnessPal, Lose It, and Cronometer are food loggers — their value is the food database, barcode scanning, and the daily diary, not the calorie estimate at setup. In MyFitnessPal, the calorie goal is free, but barcode scanning, custom macro goals, and an ad-free diary are Premium-gated.[4] So the honest split is: use a free calculator to get your starting number and your deficit plan, then decide separately whether a paid logger's database is worth the subscription for day-to-day tracking. If you are weighing loggers, our MyFitnessPal vs Cronometer comparison and MacroFactor vs Cronometer comparison cover what you actually pay for.
The one thing a paid app can do that a static calculator cannot is adapt your target over time from your logged weight trend. But you can replicate the core of that for free: pick a starting deficit, hold it for two to three weeks, and adjust based on whether your weight trend moved as projected. The calculator gives you the hypothesis; your scale gives you the correction.
Which formula your calculator uses matters less than you think
People worry about whether a tool uses Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle. In practice the spread between equations is smaller than the error from picking the wrong activity multiplier or misjudging your portions. Our comparison of TDEE formulas and the Mifflin vs Harris-Benedict vs Cunningham methodology piece show the differences are typically a few percent — well inside the 10% real-world error band any of these equations carries. Pick a tool that shows its math, then let your weight trend correct it.
Decision guidance
- You just want your number for free: the BMR Calculator for resting and maintenance, the TDEE Calculator for total expenditure.
- You want a fat-loss plan, not just a number: the Calorie Deficit Calculator — daily target, % of TDEE, and a projected timeline with an aggressive-plan warning.
- You want a food database and barcode scanning: a logger like MyFitnessPal or Cronometer, accepting that the genuinely useful parts are Premium-gated.[4]
- You are choosing between loggers: read our MyFitnessPal vs Cronometer and MacroFactor vs Cronometer comparisons first.
FAQ
What is the best free TDEE calculator in 2026?
Any calculator that uses the Mifflin-St Jeor equation, shows its math, and does not require an account. Our free TDEE Calculator and BMR Calculator meet that bar, and pairing them with the Calorie Deficit Calculator turns the estimate into a dated fat-loss plan.[1]
Is a paid app's calorie number more accurate than a free calculator?
No. They use the same Mifflin-St Jeor math, which is accurate to within 10% of measured resting metabolism for about 70-82% of people. What a paid app adds is logging and trend-based adjustment, not a better starting estimate.[2]
Does MyFitnessPal give you a TDEE?
Not directly. It returns a daily calorie goal from a Mifflin-St Jeor BMR times an activity bucket you select, then expects you to log exercise separately and add it back. The calorie goal is free; barcode scanning and custom macros are Premium-gated.[3][4]
How do I know if my calculated calories are right?
Treat the number as a hypothesis. Hold the target for two to three weeks of honest logging; your real expenditure is whatever keeps your weight trend moving as projected. Adjust from the trend, not from the equation.
Which TDEE formula is most accurate for a lifter who knows their body fat?
Katch-McArdle, because it works from lean body mass rather than total weight, so a muscular lifter with a known body-fat figure gets a less biased resting estimate than a weight-only equation. In practice the gap is small: the spread between Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle is typically a few percent — inside the 10% real-world error band any of them carries. If you do not know your body fat, Mifflin-St Jeor is the safe default.[1]
Which TDEE formula is most accurate for an endurance athlete?
For an endurance athlete, the choice of resting equation matters less than the activity multiplier and logged training load, since most of your expenditure sits in exercise, not resting metabolism. Mifflin-St Jeor with an honest activity factor, corrected against your two-to-three-week weight trend, beats fixating on which resting formula a tool uses.[1]
Best free calorie calculator that doesn't need an account and shows its math?
The aifithub TDEE Calculator and BMR Calculator run Mifflin-St Jeor in your browser with no account and a linked methodology page. If you specifically need a food database and barcode scanning for macros, a logger like MyFitnessPal or Cronometer covers that, accepting that the genuinely useful parts are Premium-gated.[1][4]
References
- 1 A new predictive equation for resting energy expenditure in healthy individuals (Mifflin-St Jeor) — American Journal of Clinical Nutrition (Mifflin et al.) (1990)
- 2 Bias and accuracy of resting metabolic rate equations in non-obese and obese adults (Mifflin within 10% for ~70-82%) — Clinical Nutrition (Frankenfield et al.) (2013)
- 3 How to Calculate Your Caloric Needs (calorie-goal methodology) — MyFitnessPal Blog (2024)
- 4 What are the features of MyFitnessPal Premium? (barcode scanning and custom macros are Premium-gated) — MyFitnessPal Help Center (2026)
- 5 MyFitnessPal Premium subscription plans and pricing — MyFitnessPal (2026)