Treadmill pace converter
Treadmill speed in km/h or mph to running pace in min/km or min/mile, at any incline.
What that pace is worth
Held all the way, flat belt. Incline not counted.
| Distance | Time at this speed |
|---|
The conversion
pace (minutes per unit) = 60 ÷ speed (units per hour)
The trap is mixing units. A mile is exactly 1609.344 metres, so 12 km/h is 7.46 mph, not 7.5.
Speed to pace chart
Every belt speed from 6 to 20 km/h.
| km/h | mph | Pace /km | Pace /mile | 5K | Marathon |
|---|---|---|---|---|---|
| 6 | 3.73 | 10:00 | 16:06 | 50:00 | 7:01:57 |
| 6.5 | 4.04 | 9:14 | 14:51 | 46:09 | 6:29:30 |
| 7 | 4.35 | 8:34 | 13:48 | 42:51 | 6:01:40 |
| 7.5 | 4.66 | 8:00 | 12:52 | 40:00 | 5:37:34 |
| 8 | 4.97 | 7:30 | 12:04 | 37:30 | 5:16:28 |
| 8.5 | 5.28 | 7:04 | 11:22 | 35:18 | 4:57:51 |
| 9 | 5.59 | 6:40 | 10:44 | 33:20 | 4:41:18 |
| 9.5 | 5.9 | 6:19 | 10:10 | 31:35 | 4:26:30 |
| 10 | 6.21 | 6:00 | 9:39 | 30:00 | 4:13:10 |
| 10.5 | 6.52 | 5:43 | 9:12 | 28:34 | 4:01:07 |
| 11 | 6.84 | 5:27 | 8:47 | 27:16 | 3:50:09 |
| 11.5 | 7.15 | 5:13 | 8:24 | 26:05 | 3:40:09 |
| 12 | 7.46 | 5:00 | 8:03 | 25:00 | 3:30:59 |
| 12.5 | 7.77 | 4:48 | 7:43 | 24:00 | 3:22:32 |
| 13 | 8.08 | 4:37 | 7:26 | 23:05 | 3:14:45 |
| 13.5 | 8.39 | 4:27 | 7:09 | 22:13 | 3:07:32 |
| 14 | 8.7 | 4:17 | 6:54 | 21:26 | 3:00:50 |
| 14.5 | 9.01 | 4:08 | 6:40 | 20:41 | 2:54:36 |
| 15 | 9.32 | 4:00 | 6:26 | 20:00 | 2:48:47 |
| 15.5 | 9.63 | 3:52 | 6:14 | 19:21 | 2:43:20 |
| 16 | 9.94 | 3:45 | 6:02 | 18:45 | 2:38:14 |
| 16.5 | 10.25 | 3:38 | 5:51 | 18:11 | 2:33:26 |
| 17 | 10.56 | 3:32 | 5:41 | 17:39 | 2:28:55 |
| 17.5 | 10.87 | 3:26 | 5:31 | 17:09 | 2:24:40 |
| 18 | 11.18 | 3:20 | 5:22 | 16:40 | 2:20:39 |
| 18.5 | 11.5 | 3:15 | 5:13 | 16:13 | 2:16:51 |
| 19 | 11.81 | 3:09 | 5:05 | 15:47 | 2:13:15 |
| 19.5 | 12.12 | 3:05 | 4:57 | 15:23 | 2:09:50 |
| 20 | 12.43 | 3:00 | 4:50 | 15:00 | 2:06:35 |
What an incline costs
Uphill costs more than you'd think, and downhill gives back much less than it takes. Figures from Minetti et al. (2002), the same curve behind grade-adjusted pace on most platforms.
Cost relative to the flat, and the flat pace costing the same as 5:00 min/km on that gradient. Minetti et al. (2002).
| Gradient | Cost vs flat | Effort-equivalent flat pace |
|---|---|---|
| -35% | -16% | 5:56 /km |
| -30% | -32% | 7:19 /km |
| -25% | -44% | 8:53 /km |
| -20% | -50% | 10:00 /km |
| -18% | -51% | 10:06 /km |
| -15% | -49% | 9:48 /km |
| -10% | -40% | 8:22 /km |
| -8% | -35% | 7:38 /km |
| -6% | -28% | 6:55 /km |
| -5% | -24% | 6:33 /km |
| -4% | -20% | 6:13 /km |
| -3% | -15% | 5:53 /km |
| -2% | -10% | 5:34 /km |
| -1% | -5% | 5:17 /km |
| 0% | +0% | 5:00 /km |
| +1% | +6% | 4:44 /km |
| +2% | +11% | 4:29 /km |
| +3% | +17% | 4:16 /km |
| +4% | +24% | 4:03 /km |
| +5% | +30% | 3:51 /km |
| +6% | +37% | 3:39 /km |
| +8% | +51% | 3:19 /km |
| +10% | +66% | 3:01 /km |
| +12% | +81% | 2:45 /km |
| +15% | +106% | 2:26 /km |
| +20% | +150% | 2:00 /km |
Two things the shape of that curve tells you it isn't symmetric, and downhill isn't a straight line
It isn't symmetric. A 5% climb costs far more than a 5% descent saves, which is why a rolling course is always slower than a flat one with the same total elevation change.
And downhill isn't a straight line. Cost bottoms out around −18%, where a metre runs about half the price of the flat, then climbs again below that. Past a certain steepness braking costs more than gravity hands back.
This is a cost model, not a pace prediction. It tells you what a gradient costs in energy, not what you would actually run on it. That depends on your downhill technique, the surface, and how much your quads have left.
The 1% incline rule
It only applies above about 12.9 km/h (8 mph). On a slow run, 1% makes the treadmill harder than the road rather than equal to it.
Where the rule comes from Jones & Doust, 1996
The advice to set 1% to "match outdoor running" traces to one study. Jones and Doust (1996) found that a 1% gradient made the oxygen cost of treadmill running equal to running outdoors, at speeds above about 8 mph (12.9 km/h). That last part usually gets dropped. Below that speed the correction needed is smaller, and at easy recovery paces it is close to zero.
Questions
How do I convert treadmill speed to pace?
Divide 60 by the speed. At 12 km/h that is 60 ÷ 12 = 5 minutes per kilometre. Same rule in imperial: at 7.5 mph, 60 ÷ 7.5 = 8 minutes per mile. Converting between the two, a mile is 1609.344 metres, so 12 km/h is 7.46 mph and 5:00 min/km is 8:03 min/mile.
What incline should I set to match outdoor running?
1% is the usual advice, and it comes from a 1996 study by Jones and Doust. They found a 1% gradient matched the oxygen cost of running outdoors, but only above about 8 mph (12.9 km/h). Below that the correction needed is smaller, and at easy paces it is close to nothing. Set 1% for a slow recovery run and you are making it harder than the road, not equal to it.
Why does treadmill running feel easier than outdoors?
Mostly because there is no air to push through, which is what the 1% convention compensates for at faster speeds. The belt does not pull your legs through, whatever you have heard: you still accelerate each leg yourself. But no wind, no camber, no turns and no pace variation all make the same speed cost a little less. Heat pushes the other way. Without airflow you overheat faster, which is why the same pace can feel harder in a warm gym.
How much harder is running uphill?
More than most people expect, and it does not balance out. On the Minetti et al. (2002) curve, a 5% incline costs about 30% more energy per metre than the flat and a 10% incline about 66% more. A 5% descent gives back only about 24%. Below about 18% down the cost starts climbing again, because braking becomes the expensive part. The full table is on this page.
Is treadmill distance accurate?
Only as accurate as the belt calibration, which drifts with wear and varies between machines. Gym treadmills can be several percent out in either direction. If your treadmill and your watch disagree, neither one is right. Stick to the same machine and read the number as a relative measure, not an absolute one.
The converter, in your pocket at the gym
Same converter, plus a metronome for cadence and your personal bests. No signal needed in a basement gym.