Free weight, BMI & calorie calculators
Quick, honest calculators for the numbers that come up when you’re tracking your weight — each one explains its formula, shows a worked example and cites its sources. Nothing you type leaves your browser.
Convert units
Track your weight
How much you’ve lost or gained, as a percentage of your starting weight.
Start, now and goal: total change, % of the way there and your average per week.
Enter your weigh-ins and see the 7-day trend line and your average weekly change.
How far your goal is, as weight and %, with BMI at goal and a date at your own pace.
Body mass index in metric or imperial, with the adult categories and what BMI can’t tell you.
Nutrition
BMI chart & calories
The GLPily app
Want this done for you, every day?
GLPily logs your weight, protein, water, meals, symptoms and measurements in one place, draws your trend and weekly average, and builds a PDF report for appointments. Free on iPhone and Android.
Free to download. Pro is an optional subscription for extras like the GLPily Grade for food and unlimited photo scans.
About these tools
They’re built by the team behind GLPily, a tracking app for people on a weight-management journey. Every calculator does plain arithmetic — the formula is on the page — and the reference values (BMI categories, protein and water ranges) come from public health bodies and peer-reviewed sources linked at the bottom of each page.
They’re for information, not medical advice: they don’t know your health history, and they never suggest a treatment, a diet or a rate of weight loss.
Informational only, not medical advice. These calculators do simple arithmetic on the numbers you enter. They don’t diagnose anything and don’t replace your clinician or dietitian. Nothing you type is sent anywhere — it stays in your browser. Updated September 2026.