Power to weight

Watts per kilo is the number cyclists talk about on climbs. Here it is, with the bike weight included, because you carry that up hills too.

Your details

200 W at 11 st 0 lb

2.86 W/kg

watts per kilogram

Per pound1.30 W/lb
With the 9.0 kg bike (what a hill feels)2.54 W/kg
With 10 more watts3.01 W/kg
On a bike 1 kg lighter2.57 W/kg
On a steady 6% climb8.2 mph (13.2 km/h), 4:33 a kilometre, climbing 791 m an hour
10 more watts on that climbsaves about 12 seconds a kilometre
A bike 1 kg lighter on that climbsaves about 3 seconds a kilometre

Watts per kilo matters on climbs; on the flat, raw watts and how tucked you are matter more. Getting stronger is the friendly route to a better number; eating less to chase it usually backfires.

If you find yourself cutting food to hit a power to weight number, Beat (0808 801 0677) and your GP can help.

The working

200 watts at 11 stone

200 W ÷ 69.9 kg = 2.86 W/kg. With a 9 kg bike and kit, the climb sees 200 ÷ 78.9 = 2.54 W/kg. Ten more watts lifts the rider figure to 3.01.

Where it matters

Hills and flats

Terrain	What counts most
Long climbs	watts per kilo
Flat roads	raw watts and how aero you are
Rolling roads	a bit of both

Ways to improve

Get stronger

Regular steady endurance rides
One interval session a week
Strength work for legs and core
Eat enough to train well

On a real hill

What the number means on a climb

Pick a gradient and the page turns your watts and weight into a climbing speed with the Martin model (gravity, rolling resistance and air, typical road bike values in still air). For a 75 kg rider on a 9 kg bike at 250 watts, an 8% climb goes at about 12 km/h, just under 5 minutes a kilometre, climbing close to 970 metres an hour.

It also shows the trade off people ask about most. In that example 10 more watts saves about 11 seconds a kilometre, while a bike 1 kg lighter saves about 3. Getting a little fitter usually beats spending money, and both beat eating less.

Read with care

What this cannot tell you

Body compositionIt says nothing about your health.
Power metersDifferent meters can read a few per cent apart.
RacingTactics and pacing win more races than numbers.

Questions

Common questions

How do I work out watts per kg?

Divide your power in watts by your weight in kilograms.

Should I lose weight to improve it?

Not as a goal in itself. Building power is healthier, and under fuelling hurts performance and health.

Does bike weight matter?

A little on long climbs, much less than your fitness.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Before you push on

New to exercise, or got a heart, lung or joint condition? Have a word with your GP or practice nurse first. Stop and get help if you feel chest pain, faintness or unusual breathlessness, and call 999 if it is severe.