Free Tools
Free, evidence-based calculators built on the same research that informs our articles. Just the numbers you need.
Find your personalised Zone 2 training range and all 5 heart rate zones using the Karvonen (heart rate reserve) formula. Enter age and resting HR, instant results.
Calculate your daily protein target based on body weight, activity level, and goal. Grounded in the 1.6–2.2 g/kg research consensus (Morton et al. 2018, ISSN 2017).
Estimate your daily calorie target for fat loss, maintenance, or muscle gain. Uses the Mifflin-St Jeor equation with activity and goal adjustments, plus a full macro breakdown.
Every formula and range is grounded in peer-reviewed research, not marketing claims or arbitrary rules of thumb.
Calculators that account for individual variables (resting heart rate, weight, activity level) give more accurate targets than generic charts.
These tools are free because accurate information should be accessible. No email required, no trial, no paywall.