Do The Impossible
A suite of precision tools designed to help you calculate, track, and optimize your performance limits.
Macro Calculator
Calculate BMR, TDEE, and exact nutrient splits for fat loss or muscle gain.
Launch ToolRunning Calculator
Predict your marathon, half-marathon, and 5k times based on recent performance.
Launch Tool1-Rep Max
Calculate your theoretical strength limits safely without maxing out.
Launch ToolPercentage Chart
Generate a printable percentage grid for weightlifting based on your 1-Rep Max.
Launch ToolPlate Calculator
Quickly calculate exactly which plates to load on the bar for any weight.
Launch ToolHR Zones
Optimize your endurance training by calculating your specific heart rate zones.
Launch ToolThe Impossible Family
⚠️ Disclaimer: These calculators are for informational purposes only and not medical advice. Consult a physician before starting any new diet or exercise program.
By using these tools, you assume all risks and agree that Impossible Fitness is not liable for any injuries or health issues.