Quick answer: at 3 mph on flat ground, a 160 lb (72.6 kg) walker burns about 246 kcal an hour, or 185 kcal in 45 minutes (129 kcal net of resting). Walk the same 45 minutes up a steady 5% slope and the figure rises to about 301 kcal.
Using the calculator
Fill in body weight and how long you walked. Then give your speed, the distance or a step count: a map app usually shows distance, a phone or tracker shows steps, a treadmill shows speed. If you enter both distance and time, those two set the speed. With steps, add your step length and the speed sets the time. The slope field is for a hill or an inclined belt; leave it at zero for a flat route.
From steps to calories
A step counter gives steps, not distance, so the calculator needs your step length to turn one into the other. 10,000 steps at a measured 30 inch step is 4.73 miles. At 3 mph that takes 1:34:42, and the 160 lb walker burns about 389 kcal, close to 39 kcal per 1,000 steps. A 130 lb walker covering the same steps burns about 316 kcal and a 190 lb walker about 462. A shorter step means less distance for the same count, and so fewer calories.
A walk worked through
3 mph is 80.5 metres a minute. Oxygen use: 0.1 x 80.5 + 3.5 = 11.5 ml per kg each minute. For 72.6 kg that is 0.84 litres a minute, and at 4.9 kcal per litre about 4.1 kcal a minute. Over 45 minutes: about 185 kcal. With a 5% grade, add 1.8 x 80.5 x 0.05 = 7.2 to the oxygen figure, and the total climbs to 301 kcal.
Where the equation comes from
The American College of Sports Medicine gives walking oxygen cost as VO2 = 0.1 x speed + 1.8 x speed x grade + 3.5 (ml per kg per minute, speed in metres per minute, grade as a decimal). Its metabolic table states the equation is most accurate from 1.9 to 3.7 mph (50 to 100 m/min) and converts oxygen at 4.9 kcal per litre. Two things follow from the maths. First, slope matters a lot: the grade term is 18 times the flat term per unit of grade, which is why hills feel so expensive. Second, on the flat the net cost of a mile is about 57 kcal for this 160 lb walker at any walking pace, while the gross cost per mile falls a little as you speed up (about 95 kcal at 2 mph, 82 at 3 mph, 79 at 3.5 mph), because the resting share is spread over less time.
Things to keep in mind
- These are population estimates. Your own stride, footwear, surface and fitness will make the real figure higher or lower.
- Outside 1.9 to 3.7 mph the tool still answers, but warns you. At a jog, the running equation suits better.
- Fitness trackers often count steps and heart rate in their own way, so their totals rarely match.
- Do not read this as a promise of weight change; that depends on far more than one walk.
On a trail with a pack, the hiking calorie calculator fits better. For a gym belt, use the treadmill calorie calculator, and to compare with a run see the running calorie calculator. Any other activity? Try the calories burned calculator. Mixing running and walking? The run walk timer beeps each change.
Sources: ACSM's Guidelines for Exercise Testing and Prescription, Table 7.3 metabolic calculations (as reproduced by Texas Tech University); ACSM's Guidelines for Exercise Testing and Prescription (Wolters Kluwer). Rules checked . Found a problem? Tell us.
Questions
How many calories does walking a mile burn?
About 82 kcal for a 160 lb person at 3 mph on the flat, or 57 kcal net of what the body uses at rest. A heavier walker burns proportionally more, a lighter one less.
Does walking uphill burn more calories?
Yes, a lot more. In the ACSM equation each 1% of grade adds 1.8 x speed x 0.01 to oxygen use. At 3 mph a 5% slope raises the hourly burn for a 160 lb walker from about 246 to about 401 kcal.
Is walking or running better for burning calories per mile?
Running costs more per mile. In the ACSM equations the speed term for running (0.2) is double the walking one (0.1), so the net cost of a flat mile running is about twice that of walking it.
How many calories do I burn walking for an hour?
For a 160 lb person on flat ground: about 189 kcal at 2 mph, 218 at 2.5 mph, 246 at 3 mph and 275 at 3.5 mph. Enter your own weight above for your figure.
How many calories do 10,000 steps burn?
For a 160 lb walker with a 30 inch step at 3 mph on the flat, about 389 kcal (4.73 miles). Your own step length and weight change the answer, so enter both above.