Enter your sex, age, weight, and height (metric or imperial), pick an activity level, and BMR plus TDEE update as you type.
Use the result to set a starting calorie target for maintaining, losing, or gaining weight - the loss and gain figures sit 500 kcal/day either side of your maintenance number. Everything runs locally in this browser tab; nothing is uploaded and no account is required.
TDEE & Calorie Calculator
Estimate daily calorie needs from sex, age, weight, height, and activity level.
Key features
- Enter sex, age, weight, and height in either metric or imperial units, then pick an activity level.
- No upload and no account - the calculation runs locally in your browser.
How it works
Uses the Mifflin-St Jeor formula to estimate BMR (calories at rest), then applies your activity level to get TDEE (total daily energy expenditure) and a loss/gain target 500 kcal/day either side of maintenance.
When to use it
Use this calculator when you want a calorie target for maintaining, losing, or gaining weight - it is not the same check as the BMI calculator (weight-for-height only, no calorie number). Not sure this is the right fit? See when to use the TDEE & calorie calculator.
Limits
Does not account for medical conditions, medications, or individual metabolic variation - this is a population-average estimate, not medical or nutritional advice.
What happens when you switch units or enter an out-of-range value
TDEE & Calorie Calculator does not convert the number already sitting in the weight or height box when you switch the metric/imperial toggle - it only relabels the field and reinterprets those same digits under the new unit. If you typed 70 while "Metric" was selected and then switch to "Imperial", the box still reads 70, but the calculation now treats it as 70 lb instead of 70 kg, so re-enter both weight and height after switching units. Age is raised to a floor of 15 if you type anything lower, and falls back to 30 if the field cannot be read as a number at all. The activity-level dropdown defaults to moderate (1.55x) when no level is present and never applies less than the sedentary floor (1.2x). A weight or height of zero or less, checked after the unit conversion above, blocks the estimate with an inline message instead of showing a wrong number.
Why the numbers update without a submit button
TDEE & Calorie Calculator has no calculate button and no separate "recalculate" step. Every field is wired to refresh all four outputs together - BMR, TDEE, and both the loss and gain targets - the instant you type a digit or pick a new option.
Frequently Asked Questions
What does TDEE & Calorie Calculator do?
Estimate daily calorie needs from sex, age, weight, height, and activity level.
When should I reach for tdee & calorie calculator?
Use it to set a starting calorie target for maintaining, losing, or gaining weight.
How is the calorie estimate calculated?
Uses the Mifflin-St Jeor formula for BMR, then applies an activity multiplier to estimate total daily energy expenditure (TDEE), with a loss and gain target 500 kcal/day either side of maintenance.
Does switching between metric and imperial convert the numbers I already typed?
No. TDEE & Calorie Calculator reinterprets the same digits under the new unit instead of converting them, so re-enter your weight and height after switching units.
What happens if I type an age younger than 15?
The calculator raises it to 15, the youngest age it will estimate for. An age field that cannot be read as a number falls back to 30 instead.
What activity level does TDEE & Calorie Calculator use if none is selected?
It falls back to moderate (1.55x); the lowest multiplier it will ever apply is sedentary (1.2x).
What happens if weight or height is zero?
TDEE & Calorie Calculator shows "Enter a weight and height greater than zero" instead of a number, checked after converting whichever unit you have selected.
Do I need to click a button to see the estimate update?
No. BMR, TDEE, and the loss/gain targets recompute the instant you type a digit or change any dropdown, including the activity level and the metric/imperial toggle.