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Treadmill incline calculator

Short answer

Running uphill costs more energy per metre: Minetti et al.'s fitted curve puts it at 3.6 J/kg/m on the flat and 4.7 J/kg/m at a 5% incline. So 10 km/h at 5% takes about the energy of 13.0 km/h on flat ground. For everyday runs, a 1% incline is enough to match the effort of running outdoors.

Last reviewed 27 October 20262 published sourcesNot medical advice

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Treadmill incline calculator

Estimates the flat-ground speed that costs the same energy as your treadmill speed and incline.

Units
km/h
%

Treadmill incline is rise ÷ run, so 1% is a 1 m rise per 100 m.

Enter your treadmill speed and incline.

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Flat-ground equivalent speed by treadmill speed and incline
Incline8 km/h10 km/h12 km/h
0%8.0 km/h (7:30 /km)10.0 km/h (6:00 /km)12.0 km/h (5:00 /km)
1%8.4 km/h (7:06 /km)10.6 km/h (5:41 /km)12.7 km/h (4:44 /km)
2%8.9 km/h (6:44 /km)11.1 km/h (5:23 /km)13.4 km/h (4:29 /km)
3%9.4 km/h (6:23 /km)11.7 km/h (5:07 /km)14.1 km/h (4:16 /km)
5%10.4 km/h (5:46 /km)13.0 km/h (4:37 /km)15.6 km/h (3:51 /km)
8%12.1 km/h (4:58 /km)15.1 km/h (3:59 /km)18.1 km/h (3:19 /km)
10%13.3 km/h (4:31 /km)16.6 km/h (3:37 /km)19.9 km/h (3:01 /km)
15%16.5 km/h (3:38 /km)20.6 km/h (2:55 /km)24.7 km/h (2:26 /km)
Speed × Cr(incline) ÷ Cr(flat), with Cr from Minetti et al. (2002).

How the estimate works

Minetti et al. measured the energy cost of running from −45% to +45% slopes and fitted it with Cr = 155.4i⁵ − 30.4i⁴ − 43.3i³ + 46.3i² + 19.5i + 3.6 J/kg/m, where i is the slope as a fraction (Minetti et al., 2002). The calculator multiplies your treadmill speed by Cr at your incline, divided by Cr on the flat.

Air resistance is missing indoors, so treadmill running is a little easier than the road at the same speed. Testing trained runners at 2.92–5.0 m/s (about 10.5–18 km/h), Jones and Doust found a 1% grade reflected the energy cost of outdoor running most accurately (Jones & Doust, 1996).

Turn a speed into pace and finish times with the pace calculator, or see what the run burns with the calories burned calculator.

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Common questions

What treadmill incline equals running outside?

A 1% incline. In a study of trained runners, a 1% treadmill grade most accurately reflected the energy cost of running outdoors on level road, which costs a little more because of air resistance.

How much harder is running uphill?

On the curve Minetti et al. fitted to their measurements, the energy cost of running rises from 3.6 J/kg/m on the flat to 6.0 at a 10% incline, about 66% more per metre.

Is this my race pace on the flat?

No. It matches energy cost, not how running uphill feels or loads your legs and heart, so treat it as a rough guide to effort rather than a pace prediction.

Sources

Figures on this page were checked against these publications on 27 October 2026.

  1. Minetti AE, Moia C, Roi GS, Susta D, Ferretti G. Energy cost of walking and running at extreme uphill and downhill slopes. Journal of Applied Physiology. 2002;93(3):1039–1046. doi.org/10.1152/japplphysiol.01177.2001
  2. Jones AM, Doust JH. A 1% treadmill grade most accurately reflects the energetic cost of outdoor running. Journal of Sports Sciences. 1996;14(4):321–327. doi.org/10.1080/02640419608727717

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