The Tools
All 15 Calculators
Every tool is free, works without signing up, and includes a full guide and FAQ.
VeltaCalc is a free collection of fitness calculators built for the UK market. No sign-up walls. No pop-ups on load. No upsells before you've even seen the tool. Just fast, accurate calculators that work.
Most fitness calculator sites are terrible. They're slow, cluttered with ads before you've typed a single number, demand an email address just to see a result, and give you a number with zero context about what it actually means or what to do with it.
We built VeltaCalc because we wanted something better. Clean, fast tools that give you the number you came for, and enough context to actually use it. Every calculator on this site includes an explanation of the formula used, what the result means, and clear next steps.
We're based in the UK, and we built this with UK users in mind. That means metric units as standard, UK-relevant health guidelines (NHS ranges for BMI, UK English throughout), and tools that reflect how British people actually train and eat.
Every tool on VeltaCalc is completely free to use. No email gate, no free trial, no paywall after 3 uses. The basic calculators will always be free, that's a promise. We monetise through minimal advertising and an optional Pro tier, not by locking core functionality.
Every formula we use is backed by published research. We cite the source; Mifflin-St Jeor for TDEE, the US Navy method for body fat, the Epley formula for 1RM. We don't invent numbers. When formulas have known limitations, we tell you.
Open a tool, enter your numbers, get your result. That's it. No pop-ups asking you to subscribe before you've seen anything. No ad overlays on page load. No dark patterns. We treat users like adults who came here to get a number, not to be marketed at.
A number without context is useless. Every result includes what it means, whether it's good or bad, what the healthy range is, and what to do next. We also link to related tools so you can build a complete picture of your fitness in one place.
Every tool is free, works without signing up, and includes a full guide and FAQ.
Every formula used in VeltaCalc tools is sourced from peer-reviewed research or validated clinical practice. We use the Mifflin-St Jeor equation for TDEE (most accurate for general populations), the US Navy circumference method for body fat estimation, the Epley and Brzycki formulas for 1RM, and the Riegel formula for race time prediction. Where multiple formulas exist, we use the most accurate one for the target population, or show you all of them with an average.
Health ranges displayed on VeltaCalc (BMI categories, waist circumference thresholds, ethnicity-adjusted BMI ranges) follow NHS and Public Health England guidelines. Where UK guidelines differ from US or international standards, we use the UK figure. We note when guidelines differ by ethnicity, as the NHS recommends different BMI thresholds for South Asian, Chinese, and some other populations.
All fitness calculators produce estimates, not lab-precision results. TDEE formulas are accurate to -10% for most people. Body fat estimates from circumference measurements are accurate to -3-4%. 1RM estimates from sub-maximal sets are accurate to -2-5% for sets of 1-5 reps. We include these caveats in every tool so users understand what they're working with.
Fitness and nutrition science evolves. If a formula we use is superseded by significantly better research, we update it. If you find an error in any of our calculations, a wrong formula, an incorrect range, or outdated guidance, please email us. We take accuracy seriously and will correct errors promptly.
Have a suggestion for a new tool? Found an error in one of our calculators? Want to discuss advertising or sponsorship? We read every message.
VeltaCalc is for informational and educational purposes only. The calculators on this site provide estimates based on published formulas and are not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making significant changes to your diet, exercise routine, or health management. If you have a medical condition, are pregnant, or have specific health concerns, speak to your GP or a registered dietitian before using these tools to set targets.
