Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Daily calorie target
2,100
Weeks to goal
20.0
Pounds lost per week
1.00
Months to goal
4.6
Pounds to lose
20.0
Deficit as % of maintenance
19.2%
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter maintenance calories (tdee).
- 2Enter current weight (lb).
- 3Enter goal weight (lb).
- 4Enter daily deficit (cal).
- 5Read your daily calorie target on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
A pound of fat stores roughly 3,500 calories, so a 500/day deficit averages about a pound a week. Deficits beyond 25% of maintenance accelerate muscle loss and adherence failure.
Worked example
Using the values the calculator loads with:
Inputs
- Maintenance calories (TDEE): 2600
- Current weight: 195 lb
- Goal weight: 175 lb
- Daily deficit: 500 cal
Results
- Daily calorie target: 2,100
- Weeks to goal: 20
- Pounds lost per week: 1
- Months to goal: 4.6
- Pounds to lose: 20
- Deficit as % of maintenance: 19.2%
What each field means
Inputs
- Maintenance calories (TDEE)
- The maintenance calories (tdee) used in the calculation. Starts at 2600 so you have a working example on load. Accepted range: 1000–6000.
- Current weight (lb)
- The current weight used in the calculation, measured in lb. Starts at 195 lb so you have a working example on load. Accepted range: 60–600 lb.
- Goal weight (lb)
- The goal weight used in the calculation, measured in lb. Starts at 175 lb so you have a working example on load. Accepted range: 60–600 lb.
- Daily deficit (cal)
- The daily deficit used in the calculation, measured in cal. Starts at 500 cal so you have a working example on load. Accepted range: 100–1500 cal.
Results
- Daily calorie target
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Weeks to goal
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pounds lost per week
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Months to goal
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pounds to lose
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Deficit as % of maintenance
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the calorie deficit & weight loss timeline calculator work?
A pound of fat stores roughly 3,500 calories, so a 500/day deficit averages about a pound a week. Deficits beyond 25% of maintenance accelerate muscle loss and adherence failure. The underlying maths is: Weeks = (Current − goal) × 3,500 ÷ (daily deficit × 7).
What do I need to enter?
4 values: maintenance calories (tdee), current weight, goal weight, and daily deficit. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the daily calorie target result mean?
It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
Who is this tool for?
It's built for anyone tracking a health or training target and wanting the standard formula applied correctly, without a signup or an app.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Calorie Deficit Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/calorie-deficit
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/calorie-deficit" target="_blank" rel="noopener">Calorie Deficit Calculator — RevenueLab</a> (2026).</p>
Source: [Calorie Deficit Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/calorie-deficit) (2026).