Weight Loss
Estimate BMR, TDEE, calorie targets, and weight-loss timelines. Free online calculator with formulas and step-by-step solutions.
Key formula
calorie balance, BMR, TDEE, and timeline estimates
How do you estimate a weight-loss plan?
Estimate maintenance calories (TDEE) from BMR × activity, choose a calorie target below maintenance, and project timeline from the weekly deficit (about 7700 kcal ≈ 1 kg fat as a rough rule). Adjust after real weekly scale trends — not day-to-day noise.
About this tool
A weight-loss plan needs maintenance calories, a realistic deficit, and a timeline — not a single magic intake number. This page connects BMR, TDEE, calorie targets, and projected weeks so the estimate stays transparent.
How to use this calculator
- Enter realistic personal values and double-check the chosen unit system before calculating.
- Use the result as a planning estimate, not as a diagnosis or guaranteed outcome.
- Compare the output with your goal, context, and any relevant professional guidance.
- Review the steps to understand how the estimate was produced from your inputs.
Worked examples
Example 1: TDEE then deficit
If TDEE ≈ 2500 kcal/day and intake is 2000 kcal/day, deficit ≈ 500 kcal/day ≈ 3500 kcal/week — roughly 0.5 kg/week on a simple energy model.
Example 2: timeline idea
Need to lose 4 kg at ~0.5 kg/week → about 8 weeks if adherence holds. Biology and water weight make real curves noisier.
Example 3: why BMR matters
BMR is rest burn; TDEE adds activity. Cutting below a sensible floor for long periods is a common over-aggressive plan mistake.
Frequently asked questions
How does a weight-loss calculator work?
It estimates BMR and TDEE, applies a calorie target below maintenance, and converts the weekly energy gap into an approximate timeline to your goal weight.
What is the difference between BMR and TDEE?
BMR is calories at rest. TDEE is daily maintenance including activity. Weight-loss targets are usually set relative to TDEE, not BMR alone.
How fast should I lose weight?
Many educational plans use a moderate weekly pace (often near 0.5–1% of body weight). Faster targets raise adherence and health risk — this tool is not medical advice.
Why is my real progress different from the estimate?
Water, glycogen, measurement error, NEAT changes, and adherence all move the scale. Use multi-week trends and adjust the plan.
Should I use this instead of a doctor or dietitian?
No. This is an educational planning estimate. For medical conditions, medications, or aggressive goals, get professional guidance.