Embed a calculator on your site
Run a gym site, a coaching blog, or a health resource? You are welcome to put any of these calculators directly on your own pages. Copy one line of HTML — there is no signup, no fee, and no tracking script. The widget loads only the calculator itself, so it stays fast and does not set advertising cookies on your visitors.
Terms of use (short version)
- Free for any site, commercial or personal, with no attribution requirement beyond the small credit link already built into the widget.
- Please keep that credit link intact and do not wrap the iframe in a way that hides it.
- The calculators give general estimates for healthy adults, not medical advice. If your audience needs clinical guidance, say so alongside the widget.
- We may change a formula if better evidence appears — see our methodology. Embeds update automatically, so you always show current math.
Available widgets
Each snippet is capped at 520px wide and scales down on mobile. Adjust height if your layout needs a different fit.
BMI Calculator
Body mass index with WHO categories.
Preview the full version: BMI Calculator
<iframe src="https://www.fitcalcs.app/embed/bmi-calculator" width="100%" height="620" style="border:1px solid #e5e7eb;border-radius:12px;max-width:520px" loading="lazy" title="BMI Calculator by FitCalcs"></iframe>BMR Calculator
Resting metabolic rate from Mifflin-St Jeor and Harris-Benedict.
Preview the full version: BMR Calculator
<iframe src="https://www.fitcalcs.app/embed/bmr-calculator" width="100%" height="760" style="border:1px solid #e5e7eb;border-radius:12px;max-width:520px" loading="lazy" title="BMR Calculator by FitCalcs"></iframe>TDEE Calculator
Daily calorie needs from body stats and activity level.
Preview the full version: TDEE Calculator
<iframe src="https://www.fitcalcs.app/embed/tdee-calculator" width="100%" height="760" style="border:1px solid #e5e7eb;border-radius:12px;max-width:520px" loading="lazy" title="TDEE Calculator by FitCalcs"></iframe>Calorie Burn Calculator
Calories burned across 46 activities using MET values.
Preview the full version: Calorie Burn Calculator
<iframe src="https://www.fitcalcs.app/embed/calorie-burn-calculator" width="100%" height="720" style="border:1px solid #e5e7eb;border-radius:12px;max-width:520px" loading="lazy" title="Calorie Burn Calculator by FitCalcs"></iframe>Want a calculator that is not listed?
We offer the four that fit cleanly in a compact frame. If you would find another one useful as a widget — macros, body fat, pace — tell us via the contact page and we will look at adding it.