Guides · Do treadmill miles count?

Do treadmill miles count toward your weekly mileage?

By Bryan, founder of Treadwell · August 30, 2026

It is Sunday night and you are adding up the week. You ran three times on the treadmill and twice outside, and a small voice asks whether the indoor three really count.

Quick answer

Yes, treadmill miles count toward your weekly mileage. The real question is how many to log. Your log copies the display, which shows the speed you chose. Nothing on the machine, as far as I can find, checks that number against the belt. Once you know how far the belt really moves, every mile counts.

A runner sits on the edge of a home treadmill in warm evening lamp light, phone in hand, adding up the week's runs — The week's total is only as good as the miles that go into it.

The argument you have heard is about effort

Put the question to other runners and the answer comes back yes, with a footnote about effort. Indoors there is no air to push against, so a flat treadmill mile is a little easier than a road mile. A gentle incline is the usual fix, and the guides on treadmill miles vs outdoor miles and treadmill pace vs road pace cover that half in full.

So the effort side is settled. What nobody in that argument asks is whether the mile you are about to add was a whole mile.

Where the mile in your log comes from

The mile you write down starts on the display, and the display shows the speed you chose. Nothing on the machine, as far as I can find, checks that number against the belt moving under your feet. Your watch cannot referee it indoors either, with no satellites to follow.

Think of a measuring cup you picked up secondhand. The line on the side says one cup, and you trust it because it is printed there. Nobody ever poured it into a true cup to check. If it holds a little less, every batch you bake comes out a little short, and the line on the cup reads the same either way. The display's mile is that printed line. The mile you log is worth exactly as much ground as the belt moved, and the display gives you no way to tell the difference.

Train on more than one machine and you are baking from a drawer full of cups. The home treadmill, the gym one and the hotel one each hold their own amount. Your weekly total adds them together as if they all matched.

An open kitchen drawer holding a jumble of mismatched measuring cups in different materials and sizes, none marked with printed lines — Every cup in the drawer holds its own amount. Every treadmill you train on does the same.

The mile you logged and the mile the belt moved

I have logged one of those unchecked treadmill miles myself. On one machine I train on, the display read 2.3 miles at the end and my Apple Watch agreed with it. The belt had moved 2.0.

That is the gap this whole question hides. Two numbers matched, and neither one had been checked against the belt.

What a small gap does to a year of miles

Now spread a smaller gap across a whole year. Say your goal is 1,000 miles, and 400 of them happen on one treadmill whose belt runs 2 percent slower than its display. The display hands you 400 miles. The belt carried you about 392, so 8 miles in your total are miles your legs never ran.

A 1,000 mile year with 400 on one treadmill

Worked example for a belt running 2 percent slower than its display. Round numbers, not a machine I measured.

Treadmill miles the display gave you400 miles
Ground the belt actually carried you392 miles
Outdoor miles600 miles
Year total in your log1,000 miles
Year total you really ran992 miles

A belt running 2 percent fast turns the same year the other way, into 8 miles you ran and never counted.

A gap that size sits inside what one lab study found. Across four laboratory treadmills, the average belt speed came in anywhere from 2 percent under the setting to 3 percent over it. A gap like that does not wash out as the year goes on either. The guide on what a small treadmill error costs over a long run shows why it grows with the miles instead of shrinking.

Counting by time only moves the problem

You could log treadmill runs in minutes and leave the miles out of it. That keeps the display's distance out of your total, which helps. It does nothing for your pace. The pace you ran was still the display's speed, and a goal pace built from those runs takes the same gap to race day.

Count them at full value

The fix is to learn what the belt really does, once for each machine you log from. Treadwell reads that from the belt itself. Stand beside the machine, aim your phone at the running belt, and the app works out the belt's own speed from the phone's camera and LiDAR sensor. Do it on the home machine and on the gym machine, and each one's miles go into your total at their true size. From then on the number in your log is the belt's, not the display's. It needs an iPhone Pro, because only the Pro models carry that LiDAR sensor.

Make every treadmill mile count

Find out how far your treadmill's belt really moves before the miles go in your log. Treadwell needs an iPhone Pro with LiDAR.

Scan with your iPhone Pro to get the app

Tested: in our tachometer tests the app read within about 2 percent of true belt speed.

Quick answers

Do treadmill miles count toward weekly mileage? Yes, treadmill miles count toward your weekly mileage. The real question is how many to log. Your log copies the display, which shows the speed you chose. Nothing on the machine, as far as I can find, checks that number against the belt. Once you know how far the belt really moves, every mile counts.

Should I log treadmill runs by time instead of miles? Log the minutes next to the miles rather than in place of them. Your watch keeps time on its own, so the minutes do not depend on the belt at all. The miles still matter for your weekly total, so they are worth getting right.

Do treadmill miles count toward a yearly mileage goal? Yes. Indoor and outdoor miles can share one yearly total. The catch is that a treadmill's miles are only as long as its belt makes them, so a year spent mostly on one machine is the year that machine's gap matters most.

Sources.

The effort half: Jones AM and Doust JH, Journal of Sports Sciences 14(4):321-327, 1996. In trained male runners, a treadmill set to a 1 percent grade came closest to the energy cost of running on a flat outdoor road.
That the display reports a setting rather than a belt measurement is my reading of treadmill service manuals from Precor, Horizon and Matrix. They describe sensing near the motor or the front roller, or no speed sensor at all, and none describes anything reading the belt's running surface. It covers the manuals I could reach, not every treadmill made.
Watches indoors: Apple Support article 105002 says Apple Watch relies on its accelerometer for indoor runs, and Garmin's Forerunner owner's manuals say GPS is off for indoor activities, with speed and distance taken from the accelerometer.
The 2 to 3 percent range: Willwacher et al., Scientific Reports 11:2244, 2021. Seven people walked and ran on four laboratory treadmills, two of them force-instrumented research machines, and average belt speed ranged from about 98 to 103 percent of the target.
The 2.3 and the 2.0 come from one of my own runs on 13 June 2026, on a machine I train on. The display read 2.3 miles and my Apple Watch matched it. Treadwell on an iPhone 17 Pro read 2.0 that day, and that machine's standing tachometer table agrees with it. There was no handheld reading taken the same day.
The 1,000 mile year, the 400 treadmill miles and the 2 percent gap are a worked example chosen to be ordinary, not a machine I measured.