How accurate is this estimate?

It is accurate for steady-state climbing in still air. Wind, variable gradient, fatigue and road surface will all affect actual times. Expect real times to be 5-15% slower.

What power should I use?

Use the power you can sustain for the expected duration. For climbs under 20 minutes, use about 105% of FTP. For 30-60 minute climbs, use FTP. For longer, use 85-95% of FTP.

Does this account for descents?

No, this calculates time for a continuous ascent. For routes with mixed terrain, break them into segments or use the Ride Time Calculator.

BikeCalcs

Ascent Time Calculator — Estimate Climbing Time

Estimate climbing time from power, weight and gradient.

Power Output

Total Weight (rider + bike)

Average Gradient

Distance

Crr

CdA

How We Calculate This

Ascent Time Estimation

The calculator solves for steady-state speed where power output equals total resistance:

P = P_gravity + P_rolling + P_aero
Time = Distance / Speed
VAM = Elevation Gain / Time (hours)

Frequently Asked Questions

Related Calculators

Climbing Category Calculator

Classify a climb by its category based on length and gradient.

Route Gradient Calculator

Calculate gradient percentage from elevation and distance data.

Elevation Gain Calculator

Calculate total elevation gain from gradient and distance.

Descent Speed Calculator

Estimate safe descent speed based on gradient and conditions.

Wind Effect Calculator

Calculate the impact of wind on speed and power requirements.

Last updated: February 2026

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.