CoreRise Tools
Free calculators for endurance athletes.
Seven tools, one purpose: take the math off your plate so you can focus on training. Everything runs in your browser — no account, no upload, no waiting.
FTP Calculator — 20-min, Ramp & 8-min Tests
Enter your best effort from a 20-minute, ramp, or 8-minute test and get your FTP plus all seven Coggan cycling zones in watts. Everything runs in your browser — no account, no upload.
Open toolWatts per Kilogram Calculator — W/kg + Coggan Category
Your raw FTP tells you how much power you produce. Your watts per kilogram tells you how fast you climb. Enter FTP and body weight to see your W/kg and where it sits on the Coggan cycling performance chart.
Open toolHeart Rate Zones Calculator — Max HR, LTHR & Karvonen
Enter your max heart rate or your lactate threshold heart rate and get all five training zones instantly. Supports the three most common methods: percentage of max HR, Joe Friel's LTHR-based zones, and the Karvonen heart rate reserve formula.
Open toolMarathon Pace Calculator — Target Time to Splits
Enter your target marathon finish time and see the required pace per kilometer and per mile, plus every 5 km split from 5 km to the finish. Pick even splits or a negative split — the calculator does the math.
Open toolTSS Calculator — Training Stress Score & Weekly Load
Enter one workout to get its Training Stress Score, or log a full week to see total load, chronic training load (CTL), acute training load (ATL), and training stress balance (TSB) — the same numbers TrainingPeaks calls the Performance Management Chart.
Open toolSweat Rate Calculator — Your Hourly Hydration Target
Weigh yourself before and after a training session, log the fluid you drank during it, and get your sweat rate in liters per hour — the most useful single number for building a race-day hydration strategy.
Open toolCarb Loading Calculator — Body Weight → Daily Grams
Enter your body weight and race distance to see your daily carbohydrate target for the carb load period — how many grams per day, what that means for breakfast, lunch, and dinner, and how many days before the race to start.
Open tool