Weight loss calculator by date
Pick a goal weight and a date. Get the daily calories it takes, checked against safe limits.
- Daily calories and deficit
- Week-by-week timeline
- Earliest safe date if needed
Open calculatorMifflin-St Jeor
Free health calculators that show their math
Three free weight loss calculators help you plan a goal date, estimate your body fat and set a daily step goal. Each one uses a published formula, names its method on every result, and checks your plan against safe limits.
- Free, no sign-up
- Private: runs in your browser
- Science-based formulas
Choose a free calculator
Body fat calculator
Estimate your body fat with a tape measure, or from height and weight alone. Then see your weight at a goal body fat %.
- Tape measure, or height and weight
- Fat mass, lean mass, category
- Healthy range for your age
Open calculatorUS Navy method
Walking weight loss calculator
See how many steps a day it takes to reach your goal, based on your weight and your pace.
- Calories per 1,000 steps
- Daily step goal and 4-week ramp
- Goal date, with a diet option
Open calculatorCompendium 2011
Why these free health calculators are different
Each one shows the formula behind your number, checks your plan against safe limits, and keeps your data on your device.
Published formulas, cited
Every result names the formula behind it, from Mifflin-St Jeor to the Compendium of Physical Activities, so you can check the source.
- Calories
- Mifflin-St Jeor, 1990
- Body fat
- Hodgdon and Beckett, 1984
- Walking
- Compendium, 2011
- Healthy ranges
- Gallagher et al., 2000
Safety checks built in
Every plan is checked before you see it. If your date is too soon, you see why, and one tap gives you a safe date or a goal you can reach by then.
- Weekly loss
- 1% of weight, 2 lb max
- Calorie floor
- 1,200 women, 1,500 men
- Daily deficit
- 1,000 calories max
- Goal weight
- BMI 18.5 or above
Private by design
Your numbers never leave your browser. There is no account and no email, so your weight and measurements stay with you.
- Where the math runs
- In your browser
- Sign-up
- Not needed
- Never asked
- Saving your plan
- PDF, print or copy
Sources behind the math
- Mifflin-St Jeor, 1990
- Katch-McArdle
- Hodgdon and Beckett, 1984 (US Navy)
- Gómez-Ambrosi et al., Diabetes Care 2012 (ADA)
- Deurenberg, 1991 (BMI-based)
- ACE body fat categories
- Gallagher et al., 2000
- Compendium of Physical Activities, 2011
Medical weight loss with Olive
Habits first. A clinical push when your body needs it.
A calorie plan works only if you can keep to it. When hunger and cravings make that hard, GLP-1 treatment works on appetite itself. Results vary, and a licensed clinician decides if treatment is right for you.
Compounded medications are tailored to a patient's needs and are not reviewed or approved by the FDA for safety or effectiveness. Prescription required. Eligibility, prescribing, and dosing are determined individually by a licensed clinician based on your medical history. Treatment is not appropriate for everyone. Results vary.
- 14.9%
- Average body-weight loss at 68 weeks on semaglutide 2.4 mgSTEP 1, Wilding et al., NEJM 2021
- 20.9%
- Average body-weight loss at 72 weeks on tirzepatide 15 mgSURMOUNT-1, Jastreboff et al., NEJM 2022
Averages from two clinical trials of brand-name medications, both alongside lifestyle changes. Results vary.
Common questions
Quick answers on sign-up, accuracy, body fat and steps. Each calculator page explains its own method in full.
Olive is an AI health companion that helps people get unstuck with their body.
Do the free health calculators need an account?
No. All three free health calculators work without an account or an email address. The math runs in your browser, and you see your full result on the page. You can download your plan as a PDF, print it or copy a summary to keep it.
How accurate is a weight loss calculator?
Every weight loss calculator gives an estimate. Ours use published formulas, such as Mifflin-St Jeor (1990) for calorie needs, and each result names the method behind it. A smaller body needs fewer calories, so run the calculator again after every 5% you lose.
What is the most accurate way to measure body fat at home?
With a soft tape measure, use the US Navy method (Hodgdon and Beckett, 1984). It is the most precise method in our body fat calculator, with a margin of about 3.5 points either way. You measure your neck and waist, plus your hips if you are a woman. A DEXA scan is the reference standard if you want a measured number.
How many steps a day do I need to lose weight?
It depends on your weight, your pace and your goal, so the walking calculator asks for all three. For example, a 172 lb woman who walks briskly burns about 32 extra calories per 1,000 steps. Going from 5,000 to 10,000 steps a day, she would lose about 0.3 lb a week from walking alone, or about 0.8 lb a week if she also eats 250 calories less.