Deficit from true maintenance · Free
TDEE Calculator for Weight Loss
Fat loss is simple arithmetic only after you know maintenance. This page estimates your TDEE, then sizes a sustainable deficit so you are not cutting from an inflated number.
- −300–500
- kcal/day typical fat-loss deficit
- 0.25–0.5 kg
- sensible weekly loss rate
- 1.6–2.2 g
- protein per kg to protect muscle
- 2 weeks
- verify with scale averages
The context
Why weight-loss TDEE starts at maintenance
A deficit only works relative to Total Daily Energy Expenditure — the calories you burn in a full day. Cut from a number that is already 300 kcal high and you are “dieting” at maintenance. That is why people “eat in a deficit” and do not lose.
This calculator estimates TDEE first, then applies a transparent deficit factor. Pair it with weekly weight averages, not daily scale noise, and adjust by 100–200 kcal if two weeks do not match the plan.
Why the formula drifts
What usually breaks a fat-loss TDEE plan
Fix these before you slash calories harder.
01
Overstated activity
Grading yourself one tier high is the most common 200–400 kcal error.
02
Watch calories on top
If the multiplier already includes training, do not add wearable burn on top.
03
Weekend drift
Five disciplined days and two free-for-alls often erase the weekly deficit.
04
Daily scale panic
Water swings hide fat loss. Compare 7-day averages.
05
Protein too low
Under-eating protein accelerates muscle loss and makes hunger worse.
06
Sleep debt
Short sleep raises hunger and can quietly cut NEAT the next day.
Method
How this calculator gets to your number
Same Mifflin-St Jeor (or Katch-McArdle) engine as the homepage — with one extra step for this use case.
Run it with my numbers- 1
Resting burn (BMR)
Mifflin-St Jeor from age, sex, height and weight. Enter body fat and we switch to Katch-McArdle for leaner or muscular bodies.
- 2
Activity multiplier
Match the whole week — not your hardest training day. A one-tier mistake usually adds or subtracts 200–400 kcal.
- 3
Deficit sizing
A small, transparent adjustment for this page’s audience. We keep factors conservative so you can verify with a two-week weight average.
Pick a direction
How to use your weight-loss number
Pick one lane for 2–4 weeks before changing anything else.
Primary cut
— —kcal / day
Eat the adjusted number. Lift 2–3× weekly. Weigh 3–4 mornings and average them.
Get my numberDiet break
— —kcal / day
After 8–12 weeks of cutting, 1–2 weeks at maintenance can restore adherence and training quality.
Get my numberMini-cut
— —kcal / day
Only if sleep and lifts stay solid. Then return to a gentler deficit.
Get my numberHighest return first
Habits that make the deficit show up
Ranked by return on effort.
- #1
Weigh food for two weeks
Eyeballing portions is usually where the “hidden” 300 kcal lives.
- #2
Keep steps roughly steady
If NEAT crashes when you diet, the math lies. A step floor fixes that.
- #3
Protein first at meals
Hit the protein range before fretting over carbs vs fat.
- #4
Recalculate after ~5% weight loss
Smaller body, smaller TDEE. Update the target.
FAQ
Questions about TDEE weight loss
Short, direct answers. If yours is missing, ask and we will add it.
Ask a questionMost adults do well at 300–500 kcal below true maintenance. Larger cuts work briefly but often backfire on adherence and muscle.
Keep going
Related calculators & guides
Main TDEE calculator
Homepage tool — Mifflin-St Jeor with optional body fat.
TDEE for maintenance
Hold weight or take a diet break.
Main TDEE calculator
Full homepage calculator.
Two minutes