Treadmill incline calculator
Written by Jamie Irwin, Founder & EditorLast checked
A 10% treadmill incline is 5.71°, and climbs 100 m per kilometre on the belt.
Convert your own incline
What does incline mean on a treadmill?
It is a percent grade: rise divided by the horizontal distance you cover, as a percentage. A console showing 10 is describing that ratio, not an angle of 10°.
The two numbers are never close, and the gap between them is the steady part. At the bottom of the range the percent is almost exactly 1.745 times the angle: 1% is 0.57°, 5% is 2.86°, 10% is 5.71°. That multiplier then drifts UP as the grade rises, from 1.745 at 1% to 1.768 at 20%, because a tangent stops behaving like its angle.
Which means the angle grows more slowly than the grade does: 0% to 10% adds 5.71°, while 20% to 30% adds only 5.39°. Each extra ten points of grade buys slightly less angle than the ten before it.
Treadmill incline chart: percent, degrees and effort
The METs column is what the same walk costs in energy at each grade, from the ACSM walking equation, at 5 km/h throughout. The last column is that against the flat figure of 3.38 METs.
| Incline | Degrees | Rise per km on the belt | METs at 5 km/h | Against flat |
|---|---|---|---|---|
| 0% | 0° | 0 m | 3.38 | flat |
| 1% | 0.57° | 10 m | 3.81 | +13% |
| 2% | 1.15° | 20 m | 4.24 | +25% |
| 3% | 1.72° | 30 m | 4.67 | +38% |
| 4% | 2.29° | 40 m | 5.1 | +51% |
| 5% | 2.86° | 50 m | 5.52 | +63% |
| 6% | 3.43° | 60 m | 5.95 | +76% |
| 7% | 4° | 70 m | 6.38 | +89% |
| 8% | 4.57° | 80 m | 6.81 | +101% |
| 9% | 5.14° | 90 m | 7.24 | +114% |
| 10% | 5.71° | 100 m | 7.67 | +127% |
| 12% | 6.84° | 119 m | 8.52 | +152% |
| 15% | 8.53° | 148 m | 9.81 | +190% |
| 20% | 11.31° | 196 m | 11.95 | +254% |
Treadmill elevation: how much you climb
A treadmill measures distance along the belt, so the height climbed is distance x sin(arctan(grade / 100)) rather than distance times the grade. The belt reading is always the smaller and truer number: at 12% over 2.4 km the two answers are 286 m and 288 m.
| Distance on the belt | 2% | 5% | 10% | 12% | 15% |
|---|---|---|---|---|---|
| 0.5 km | 10 m | 25 m | 50 m | 60 m | 74 m |
| 1 km | 20 m | 50 m | 100 m | 119 m | 148 m |
| 1 mile | 32 m | 80 m | 160 m | 192 m | 239 m |
| 2 km | 40 m | 100 m | 199 m | 238 m | 297 m |
| 3 km | 60 m | 150 m | 299 m | 357 m | 445 m |
| 5 km | 100 m | 250 m | 498 m | 596 m | 742 m |
| 5 miles | 161 m | 402 m | 801 m | 959 m | 1194 m |
| 10 km | 200 m | 499 m | 995 m | 1191 m | 1483 m |
The 12-3-30 calculator runs the same sum for that one workout, at 12% and 3 mph for 30 minutes.
How this is calculated
Degrees are arctan(percent / 100) x 180 / pi. Height climbed is distance x sin(arctan(percent / 100)), with the distance taken as the belt reading rather than as a horizontal run.
Effort uses the ACSM walking equation: VO2 = speed x 0.1 + grade x speed x 1.8 + 3.5, with speed in metres a minute and grade as a fraction. METs are VO2 divided by 3.5. The middle term is the whole of what incline does in that equation, and it is why the METs column rises in a straight line while the degrees column does not.
The equation is sourced; the speeds it is valid over are not. The range quoted everywhere, about 1.9 to 3.7 mph for walking, traces to a site that names no edition of the ACSM guidelines. So the effort figure appears only between 3.06 and 5.95 km/h and the calculator says so above it, rather than printing a number from outside a band we could not check.
Sources
- Publisher stated, Independent publication
- The ACSM walking and running metabolic equationsTexas Tech University, Kinesiology and Sport ManagementACSM Health Fitness Instructor workshop, metabolic calculations (sample problems)Opened 19 September 2026Sets out both equations and works examples with them. Walking: VO2 = speed x 0.1 + grade x speed x 1.8 + 3.5, speed in m/min, grade as a fraction. Running uses 0.2 and 0.9. Our implementation reproduces the document’s own two worked examples exactly, 17.44 ml/kg/min at 2.5 mph and 6%, and 44.6 at 6.5 mph and 4%, which is how we checked it. GRADED D, NOT B, DELIBERATELY: the site’s B means corroborated across two or more independent sources, and this is one teaching document. We looked for a second open source stating the same coefficients and did not find one in the time we gave it, so the grade says what is true, that we took it as published and did not verify it against a second.
- Not established
- The speeds the ACSM equations are valid overNo primary source we could openThe figures are commonly quoted as about 1.9 to 3.7 mph for walking and above 5 mph for runningThe equations are sourced; their valid range is not. The figures above trace to a certification-prep site that attributes them to "ACSM’s Guidelines for Exercise Testing and Prescription" without naming an edition or page, and we could not open a primary statement of them. So the incline calculation here applies the WALKING equation only, stops at the top of that commonly quoted band, and says so rather than extrapolating past a boundary nobody has shown us.
- Independently verified, Independent publication
- One mile is exactly 1.609344 kmNIST (US National Institute of Standards and Technology)SI units — lengthOpened 19 September 2026Corroborated byWeights and Measures Act 1985 (UK)Schedule 1, Part VI: Mile = 1760 yards; YARD = 0.9144 metreOpened 19 September 2026NIST states that the inch has been exactly 25.4 mm since the international yard and pound agreement of 1959. A mile is 63,360 inches, so it is exactly 1,609.344 m. UK statute gives the same number by a different route: Schedule 1 Part VI of the Weights and Measures Act 1985 sets "Mile = 1760 yards" and "YARD = 0.9144 metre", and 1760 x 0.9144 is 1,609.344 exactly. THE CAVEAT, because it is the reason this is a B and not higher: both descend from the same 1959 international agreement, so they are independent publications rather than independent measurements. Neither copies the other, and an error in one would not reach the other, which is what the B test asks. It is a definition rather than a measurement either way, which is why every conversion on these pages is exact.
Limits
The angle and the climb are arithmetic and are exact for the numbers you type in. What they are not is a measurement of your machine: we have not checked the incline calibration of any treadmill, so a console reading 10% is a claim by the machine, not a fact about the deck.
The effort column is a population equation applied to one person walking. It takes no account of fitness, gait, holding the handrails, or the difference between a treadmill and a hill. Holding on in particular changes the answer and the equation has no term for it.
Running is deliberately not offered. The ACSM has a running equation and this library implements it, but its lower bound is part of the same unsourced range, so no page here uses it. Our guide to incline treadmills covers what the number means when you are choosing a machine rather than setting one.
Related tools
Corrections
- 19 September 2026 This page said the relationship between percent and degrees steepens as the grade rises. It flattens: 0% to 10% adds more angle than 20% to 30% does.
- 19 September 2026 It then said the two "only look alike at the bottom of the range" and differ by a hundredth of a degree at 1%. They are never alike: 1% is 0.57 degrees. The percent is about 1.75 times the angle throughout, and that multiplier drifts up rather than down.
- 19 September 2026 A "Feel" column called 7% a genuine hill. That is a claim about effort with nothing behind it, and it has been replaced by the energy cost at each grade, which has a source.
Looking for a machine rather than a number? See our guide to what the incline number means when you are choosing a machine. Every specification there carries its source and the date it was checked.