Free Tools
Embed our free health calculators
Every Catalyst healthspan calculator can be embedded on any website with one line of code. The set covers fitness age, VO2 max, grip strength, waist-to-height, protein intake and more, each free, mobile-friendly and evidence-based. Pick a calculator below, copy its snippet, and paste it into your page; it stays in sync with the live tool.
Every Catalyst calculator is free to embed on your website. One line of code, no sign-up, no API key, no cost. Each one is evidence-based and benchmarked to the reference standards, runs entirely in the visitor's browser, and collects no data. Paste the snippet yourself or send it to your web developer.
Quick answer
You can embed any of Catalyst Performance's eleven free health calculators, fitness age, VO2 max, grip strength, waist-to-height ratio, the sitting-rising test, GLP-1 muscle loss, running pace, heart-rate zones, protein intake, and body fat percentage, on any website with a single line of HTML. They are free, require no account or API key, work on mobile, and collect no visitor data. Each embed includes a small attribution link back to Catalyst Performance.
How to embed a calculator
- 1
Copy the embed code
Pick the calculator you want below and click Copy to grab its one-line embed code.
- 2
Paste it into your page
Paste the code into your page's HTML where you want the calculator to appear, using a Custom HTML / Code / Embed block on most site builders.
- 3
Publish
Publish the page. The calculator loads instantly, works on mobile, and collects no data. The attribution link is already included.
All eleven calculators
Copy a snippet and paste it into your page. Preview each tool before you embed it.
Fitness Age Calculator
Preview the tool →Estimates the age at which someone's cardiorespiratory fitness would be average, from their resting heart rate.
<iframe src="https://catalystperformance.sg/embed/fitness-age" width="100%" height="640" style="border:0;max-width:680px" loading="lazy" title="Fitness Age Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/fitness-age">fitness age calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>VO2 Max Calculator
Preview the tool →Shows a VO2 max percentile for age and sex against the FRIEND registry, or estimates it from resting heart rate.
<iframe src="https://catalystperformance.sg/embed/vo2-max-calculator" width="100%" height="720" style="border:0;max-width:680px" loading="lazy" title="VO2 Max Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/vo2-max-calculator">VO2 max calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Grip Strength Test
Preview the tool →Checks handgrip against the AWGS sarcopenia thresholds and age-and-sex percentiles.
<iframe src="https://catalystperformance.sg/embed/grip-strength-test" width="100%" height="680" style="border:0;max-width:680px" loading="lazy" title="Grip Strength Test by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/grip-strength-test">grip strength test</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Waist-to-Height Ratio Calculator
Preview the tool →Flags cardiometabolic risk against the 0.5 waist-to-height boundary.
<iframe src="https://catalystperformance.sg/embed/waist-to-height-ratio" width="100%" height="680" style="border:0;max-width:680px" loading="lazy" title="Waist-to-Height Ratio Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/waist-to-height-ratio">waist-to-height ratio calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Sitting-Rising Test
Preview the tool →Scores the floor sit-to-stand test out of 10, a no-equipment stability and mortality-linked measure.
<iframe src="https://catalystperformance.sg/embed/sit-rise-test" width="100%" height="700" style="border:0;max-width:680px" loading="lazy" title="Sitting-Rising Test by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/sit-rise-test">sitting-rising test</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>GLP-1 Muscle-Loss Calculator
Preview the tool →Estimates how much of the weight lost on a GLP-1 (Ozempic, Wegovy, Mounjaro) is likely muscle rather than fat, and how to keep it.
<iframe src="https://catalystperformance.sg/embed/glp1-muscle-loss-calculator" width="100%" height="760" style="border:0;max-width:680px" loading="lazy" title="GLP-1 Muscle-Loss Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/glp1-muscle-loss-calculator">GLP-1 muscle-loss calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Running Pace Calculator
Preview the tool →Predicts 5K, 10K, half and full marathon times and pace per km from one recent race, using Riegel's formula.
<iframe src="https://catalystperformance.sg/embed/running-pace-calculator" width="100%" height="740" style="border:0;max-width:680px" loading="lazy" title="Running Pace Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/running-pace-calculator">running pace calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Heart Rate Zones Calculator
Preview the tool →Gives the five heart-rate training zones in bpm from age, with the Karvonen method when a resting heart rate is added.
<iframe src="https://catalystperformance.sg/embed/heart-rate-zones-calculator" width="100%" height="760" style="border:0;max-width:680px" loading="lazy" title="Heart Rate Zones Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/heart-rate-zones-calculator">heart rate zones calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Fat Loss Calculator
Preview the tool →Gives an honest fat loss timeline in weeks from baseline, training and diet commitment, with the fat-versus-muscle split of the loss.
<iframe src="https://catalystperformance.sg/embed/fat-loss-calculator" width="100%" height="1000" style="border:0;max-width:680px" loading="lazy" title="Fat Loss Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/fat-loss-calculator">fat loss calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Protein Intake Calculator
Preview the tool →Gives a daily protein target in grams from body weight, with a higher target for building or keeping muscle.
<iframe src="https://catalystperformance.sg/embed/protein-intake-calculator" width="100%" height="700" style="border:0;max-width:680px" loading="lazy" title="Protein Intake Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/protein-intake-calculator">protein intake calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Body Fat Percentage Calculator
Preview the tool →Estimates body fat from tape measurements using the US Navy method, against the healthy range by age and sex.
<iframe src="https://catalystperformance.sg/embed/body-fat-percentage-calculator" width="100%" height="740" style="border:0;max-width:680px" loading="lazy" title="Body Fat Percentage Calculator by Catalyst Performance"></iframe>
<p style="font-size:13px;line-height:1.5;text-align:center;margin:8px 0">Free <a href="https://catalystperformance.sg/tools/body-fat-percentage-calculator">body fat percentage calculator</a> by <a href="https://catalystperformance.sg">Catalyst Performance</a>, a healthspan and longevity focused personal training studio in Singapore.</p>Embedding, common questions
- Are the calculators free to embed?
- Yes. All eleven are free to embed on any website, with no sign-up, no API key, and no usage limit. The only condition is keeping the small attribution link that comes with the embed code.
- Do I need any code skills or a plugin?
- No. The embed is a single line of HTML (an iframe). Paste it into your page wherever you want the calculator to appear. No JavaScript, plugin, or account needed. You can also send the code to your web developer to implement.
- How do I embed it on WordPress, Squarespace, or Wix?
- WordPress: paste it into a Custom HTML block. Squarespace: a Code block. Wix: an Embed / HTML iframe element. Webflow: an Embed element. Any plain HTML page: paste it into the page body.
- Can I change the size or style?
- You can adjust the width and height in the snippet to fit your layout, and it is responsive on mobile. The calculator's own styling stays fixed so it remains consistent and on-brand wherever it appears.
- What data do the embedded calculators collect?
- None. Each calculator runs entirely in the visitor's browser and stores nothing. There are no ads and no third-party tracking inside the embedded widget.
- Which calculators can I embed?
- All eleven: fitness age, VO2 max, grip strength, waist-to-height ratio, the sitting-rising test, GLP-1 muscle loss, the fat loss timeline, running pace, heart-rate zones, protein intake, and body fat percentage. Each is benchmarked to a named primary source (for example the FRIEND registry, the Asian Working Group for Sarcopenia, Ashwell's waist-to-height work, Riegel's race-time formula, and the US Navy body-fat method).