Calorie Deficit Calculator
Maintain and lose figures together, so the gap is visible.
FREE - NO SIGN-UP - RUNS ON YOUR DEVICE
The figures stay in this browser tab
- −500kcal when losing
- Gaptarget minus maintenance
- Liveupdates as you type
- 0data uploaded
What you can count on
- 4figures
- Target, maintenance, basal, adjustment
- All four for the goal you pick
- 0sent anywhere
- Height and weight stay in this tab
- Nothing is stored
- Est.not a plan
- General information, not medical advice
- A fixed −500 or +300 is applied
Calorie Deficit Calculator at a glance
- Input
- Age, sex, size, activity, goal
- Output
- Target, maintenance and basal
- Deficit size
- Fixed at −500 when losing
- Weight loss timeline
- No timeline is predicted
- Health notice
- Estimate, not medical advice
- Processing
- Runs locally in your browser
- Activity multipliers
- 1.2 → 1.9, default 1.375
- Goal adjustment
- −500 / +300, floor 1200 kcal
- Price
- Free
- Account required
- No
How to use Calorie Deficit Calculator
- 1
Fill in your details
Age, sex, height, weight, the activity level for an ordinary week, and a goal.
- 2
Compare the figures
The maintain and lose numbers sit together, and the distance between them is the deficit.
- 3
Keep the summary
Copy result puts the figures on your clipboard, so nothing has to be written down twice.
Frequently asked questions
How big a deficit does this set?
It sets one for you: 500 kcal below maintenance when the goal is to lose, and 300 above when it is to gain. The adjustment row shows what is left after the 1200 kcal floor.
Can it tell me when I will reach a weight?
No. It estimates daily calories for a goal and stops there. It does not project a date or a rate of change.
Which method is behind the numbers?
Mifflin-St Jeor, applied to the values you enter and your activity level. The method is named on the panel so the result can be checked.
Is a deficit safe for me?
That is a question for a qualified health professional. This is a general estimate from a formula, not advice about your own circumstances.
Reading the gap between two figures
Enter age, sex, height, weight, activity and goal. The panel shows the Mifflin-St Jeor target for the goal you picked, your maintenance figure, and the gap between them.
- The maintain figure is what everything else is measured against, so check it matches an ordinary week before reading the gap.
- Activity level moves both numbers together, which means an optimistic choice shifts the whole set.
- Estimates from different methods disagree, so treat the gap as a rough distance rather than an exact allowance.
Full specification
| Input | Age, sex, height, weight, activity level and which of the three goals you want. |
|---|---|
| Output | Mifflin-St Jeor daily calorie estimate for the goal you picked, with your maintenance and basal figures beside it. |
| Deficit size | Fixed. Losing takes 500 off maintenance and gaining adds 300; the row shows the gap left after the 1200 kcal floor. |
| Weight loss timeline | Not calculated. The panel gives daily calorie estimates and stops there. |
| Health notice | This result is an estimate for general information and is not medical advice. |
| Processing | All calculations run locally in the current browser tab. |
| Activity multipliers | 1.2 sedentary, 1.375 lightly active, 1.55 moderately, 1.725 very, 1.9 extra. The box starts on 1.375, not sedentary. |
| Goal adjustment | Lose takes 500 off maintenance, gain adds 300. The target never goes below 1200 kcal, even when the deficit would take it there. |
| Price | Free |
| Account required | No |
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