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Energy

Body weight planner

Explore a dynamic weight-change scenario with a goal date and a transparent model.

Free · No account neededMethod & sources

YOUR INPUTS

Your measurements

Measurement units
Energy units

The source equations are published separately for males and females. Choose the category the equation uses.

Accepts ages 18 to 85.

Daily energy divided by resting energy. Use a value from 1.4 to 2.3. How to choose an activity level

Inputs stay in this browser.

YOUR RESULT

Start with your numbers.

Explore a dynamic weight-change scenario with a goal date and a transparent model. Complete the fields to see the calculation, method, and limits.

PERCENT LOST

Weight loss percentage calculator

See what share of your starting weight you have lost, and the weights at 5% and 10% below where you started.

Example: from 90 kg to 85.5 kg is 5.0% lost, and so is the CDC's example of 200 lb to 190 lb (5.0%). 10% below 90 kg is 81.0 kg, and 10% below 200 lb is 180 lb.

Percent lost = (starting weight − current weight) ÷ starting weight × 100. Weight at a percentage lost = starting weight × (1 − percentage ÷ 100).

YOUR INPUTS

Your measurements

Measurement units

Inputs stay in this browser.

YOUR RESULT

Start with your numbers.

See what share of your starting weight you have lost, and the weights at 5% and 10% below where you started. Complete the fields to see the calculation, method, and limits.

UNDERSTAND THE METHOD

How to use this calculator

Enter an adult profile, goal weight, physical activity level, and dates. This model keeps physical activity fixed and assumes carbohydrate supplies half of daily energy. It solves for the intake that reaches the chosen weight in the model.

What the result can tell you

The model is for adult scenarios, not pregnancy or breastfeeding. It is not a personal intake prescription or an exact reproduction of the NIH Body Weight Planner. Food composition, sodium, adherence, and individual physiology can change a real trajectory. Dates are model estimates.

Common questions

What does the body-weight planner solve?

Enter an adult profile, goal weight, activity level, and dates. The model keeps activity fixed, assumes carbohydrate supplies half of daily energy, and solves for the intake that reaches the selected weight in the model.

Is the result a personal calorie prescription?

No. It is an adult scenario model and is not an exact reproduction of the NIH Body Weight Planner. Food composition, sodium, adherence, and individual physiology can change a real trajectory.

How do I calculate the percentage of weight I have lost?

Subtract your current weight from your starting weight, divide by your starting weight, and multiply by 100. From 200 lb to 190 lb is 10 ÷ 200 × 100 = 5% lost, which is the CDC's own example of modest weight loss. In kilograms, 90 kg to 85.5 kg is also 5%.

Sources & limitations4 sources

Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.

  1. Hall and colleagues describe a dynamic energy-balance model.pmc.ncbi.nlm.nih.gov
  2. The model appendix provides state equations and constants.niddk.nih.gov
  3. Body-fat estimation used to initialize the model.pubmed.ncbi.nlm.nih.gov
  4. CDC: if you are not at a healthy weight, even modest weight loss can help improve blood pressure, cholesterol and blood sugar; its example is a 5% loss, 10 pounds for a person who weighs 200 pounds.cdc.gov