Free widgets
Embed training-zone calculators on your site
Every TrainingZones calculator is a free, embeddable widget. Choose one, set the language, theme and width, then copy a single line of HTML. Free forever, no signup.
Build your embed
Embed code
<iframe src="https://trainingzones.app/embed/max-heart-rate?lang=en&theme=light" width="100%" height="640" style="border:none;border-radius:16px;max-width:100%;" loading="lazy" title="Max Heart Rate Calculator: TrainingZones"></iframe>
<p>Calculator by <a href="https://trainingzones.app/max-heart-rate">TrainingZones</a></p>Keeping the credit link is optional but genuinely appreciated; it helps other athletes find these free tools.
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All calculators
Max Heart Rate Calculator
/embed/max-heart-rate
Heart Rate Zone Calculator
/embed/heart-rate-zone-calculator
Karvonen Heart Rate Reserve Calculator
/embed/karvonen
MAF 180 Formula Calculator
/embed/maf-180
Friel LTHR Heart Rate Zone Calculator
/embed/lthr-zones
FTP Calculator & Cycling Power Zones
/embed/ftp-calculator
Critical Power Calculator (CP & W′)
/embed/critical-power
Running Power Zones Calculator
/embed/running-power
VDOT Calculator & Running Pace Zones
/embed/vdot-calculator
Critical Swim Speed (CSS) Calculator
/embed/css-calculator
Rowing Heart Rate Zones (UT2–AN)
/embed/rowing-zones
XC Skiing & Biathlon Heart Rate Zones (I1–I5)
/embed/xc-ski-zones
Ski Mountaineering Vertical Calculator
/embed/skimo-zones
Daily Calorie Calculator
/embed/daily-calories
Carbohydrate Intake Calculator
/embed/carb-intake
Sweat Rate Calculator
/embed/sweat-rate
VO2max Estimator
/embed/vo2max-estimator
BMI Calculator
/embed/bmi
Running Race Time Predictor
/embed/race-time-predictor
Frequently asked questions
- How do I embed a calculator?
- Pick a calculator, language, theme and width below, click “Copy code”, and paste the generated <iframe> snippet anywhere in your site’s HTML. The widget sizes itself to its content and works on any platform: WordPress, Webflow, Ghost, plain HTML and more.
- Is it free?
- Yes, completely free, forever. There is no signup, no account and no cost to embed any TrainingZones calculator on your site.
- Do I need to credit TrainingZones?
- It’s not required, but a credit link back to TrainingZones is genuinely appreciated. The snippet includes a small “Calculator by TrainingZones” line you’re welcome to keep; it helps other athletes find these free tools.
- Can I change the language, theme or size?
- Yes. Choose from 17 languages, a light or dark theme, and a responsive or fixed pixel width. Your selections are baked into the iframe URL, so the embed always renders exactly as you previewed it.