Triathlon and Road Cycling Race Time, Power and Speed Calculator

It solves the power equation, aerodynamic drag, rolling resistance and gravity, for each gradient segment of the course using your FTP, weight, riding position and rider level, then adds up the segment times. Upload a GPX file and it uses the real profile.

Coaching guidance for age-group athletes is 65 to 75% of FTP for the full distance, lower the longer your expected ride, and 75 to 85% for a 70.3; professionals ride a few points higher. Select "70.3 leg" or "Full-distance leg" under Ride Type and the calculator paces the bike with exactly these targets, adjusted to your expected bike time and rider level, so that you can still run.

A 25 km/h headwind at rider height, a forecast of about 40 km/h at 10 m, turns a flat 40 km at 250 W FTP from 1:00 into 1:35. The same wind from behind saves only 18 minutes. Drag grows with the square of air speed, so the headwind stretches lose more than the tailwind stretches gain; on a loop course the net effect is always a slower ride.

Yes. Set the wind speed and, with a GPX course, the direction it blows from, or enter your race date and start time and fetch the forecast for the course. Every stretch of the course then meets its own headwind, tailwind or crosswind from its riding direction, and drag is computed from the air speed you actually feel. Without a course file the ride is treated as a loop that meets the wind from all directions equally.

From Open-Meteo, which picks the best regional weather model for the course location: DWD ICON in Central Europe, Météo-France AROME, the UK Met Office model, NOAA HRRR in North America and global models elsewhere. The calculator reads the hourly wind for the course midpoint over your predicted ride window and applies its mean speed and direction; the same request brings temperature, humidity, surface pressure and cloud cover for the weather row.

Up to 15 days, usable for wind from about a week out. For races further away the calculator shows the typical wind of that calendar week from the last five years, so you can plan pacing months ahead and refresh the forecast in race week. Past dates return the recorded wind, useful for analysing a race afterwards.

Forecasts state the wind 10 m above ground. A rider sits at about one metre, where hedges, buildings and the ground itself slow the air. Following the logarithmic wind profile, the calculator applies 60% of the forecast speed on an open course, 50% on a sheltered one and 70% on an exposed one; choose the course exposure under the forecast, or press "Detect from map data" and the calculator reads the land cover along the course, classifies every stretch and applies its own share there. Adjust the slider if you know the roads.

Twice. Warm air is thinner: the drag term uses the air density of the day from temperature, humidity and the pressure at the course elevation (or the forecast's surface pressure), so 30 °C at sea level is about 6 percent less dense than 15 °C and 1000 m of altitude about 11 percent, each worth 1 to 2 percent of speed on the flat; cold air is denser and slower. Heat then lowers the power you can hold, but much less than on the run: the airflow at riding speed carries the heat away (Saunders 2005), and time trials with race-realistic fans held their power to 27 °C and lost about 6 percent at 32 °C (Peiffer and Abbiss 2011; Tatterson 2000). The calculator applies nothing up to 18 °C WBGT (computed as weather stations do, from temperature, humidity, pressure, wind and sun, Liljegren 2008), then 3 percent of sustainable power per 5 °C WBGT for an Established rider who is not acclimatised, less for stronger riders and for one to two weeks of heat acclimatisation (Racinais 2015: 16, 8 and 3.5 percent on days 1, 6 and 14), more on bike legs over 1.5 hours as a proxy for dehydration. Fetch the race-day forecast and the weather row fills itself; the result shows what the weather costs or gives, the heat penalty with the span a ±2 °C WBGT band would give (the estimate uses the midpoint).

Yes, less than a headwind but not nothing: a crosswind raises the air speed the body meets. A 25 km/h crosswind costs about 6% on a flat course. Deep wheels can recover part of that; the calculator holds the drag area constant, which is the conservative assumption.

Red stretches face a headwind, blue stretches get a tailwind, grey stretches ride in a crosswind. The strip under the elevation profile shows the same for the whole course, and hovering over the profile names the wind at that point. With the land cover detected from map data, sheltered stretches show paler colours because less of the wind reaches you there.

A 4th-power mean of your power output that weighs hard efforts more than easy ones. It shows the physiological cost of a hilly ride better than the plain average.

Yes. Under the estimated time, "Take into race plan" writes the split and the distance into the triathlon planner, which re-sums the finish time and shows where the split came from; without a plan it starts one from the preset that fits the distance. The nutrition plan takes the splits from there.