Kilometers to Miles Converter
Convert kilometres to miles with the exact relationship, then apply an IRS or HMRC rate that is published per mile — or check the distance against a per-kilometre rule before you claim it.
The conversion factor
1 kilometre = 0.621371 miles
This one is rounded, and it is worth knowing why: 1 mile is exactly 1.609344 km, so the reverse factor is 1 ÷ 1.609344, a decimal that never terminates. 0.621371 is the first six digits of it. The page divides by 1.609344 rather than multiplying by a rounded 0.62, because on 1,000 km that shortcut is out by nearly 1.4 miles.
Convert kilometres to miles
Editing the kilometres figure updates the result instantly.
Miles
62.14mi
Calculated from the exact factor.
100.00 km = 62.14 mi. Divide by 1.609344 to go from kilometres to miles. Keep the converted figure with the trip record so the claim and the log agree.
Kilometres to Miles conversion table
Common kilometre distances converted using the exact 1.609344 km per mile relationship. The tier thresholds used by the CRA, ATO, IRD and SARS are marked in the third column.
| Kilometres (km) | Miles (mi) | Landmark |
|---|---|---|
| 1.000 | 0.621 | The exact definition |
| 2.000 | 1.243 | |
| 3.000 | 1.864 | |
| 5.000 | 3.107 | A 5K run |
| 10.00 | 6.214 | A 10K run |
| 15.00 | 9.321 | |
| 20.00 | 12.43 | |
| 21.10 | 13.11 | Half marathon |
| 25.00 | 15.53 | |
| 30.00 | 18.64 | |
| 40.00 | 24.85 | |
| 42.20 | 26.22 | Marathon |
| 50.00 | 31.07 | |
| 60.00 | 37.28 | |
| 80.00 | 49.71 | |
| 100.00 | 62.14 | |
| 150.00 | 93.21 | |
| 200.00 | 124.27 | |
| 250.00 | 155.34 | |
| 300.00 | 186.41 | |
| 400.00 | 248.55 | |
| 500.00 | 310.69 | |
| 800.00 | 497.10 | |
| 1,000 | 621.37 | |
| 2,000 | 1,242.7 | |
| 3,000 | 1,864.1 | |
| 5,000 | 3,106.9 | CRA tier threshold |
| 8,000 | 4,971.0 | SARS simplified-rate cap |
| 14,000 | 8,699.2 | IRD tier threshold |
| 20,000 | 12,427.4 |
Values are computed by dividing by the exact factor, not by multiplying by a rounded one, so the table and the converter above always agree.
The km to mi formula
miles = kilometres ÷ 1.609344
Division is the whole formula. Dividing is the same as multiplying by the reciprocal, but keeping the division means you are using the one exact number rather than a truncated copy of it.
The mile was fixed at 1,609.344 metres when it was defined as 5,280 feet of exactly 0.3048 metres each. Turning that around gives 0.6213711922… miles per kilometre, a decimal that never terminates, which is why a rounded 0.62 is not good enough for a claim.
Mental shortcuts, and how far off they are
Multiply by 5 and divide by 8
About 0.6% high
The quickest mental route. Equivalently: halve the kilometres, then add an eighth of the original — the two are the same arithmetic.
Halve, then add a quarter of the halved value
About 0.6% high — the same as ×5÷8
The spoken form of the ratio above, for when there is nothing to write on. Halving gives 0.5, and the extra quarter of that brings it to 0.625.
Multiply by 0.62
About 0.2% low
A closer one-step estimate than the halves trick, if you can hold two digits. Still not close enough for a claim: on 1,000 km it is out by about 1.4 miles.
Divide by 1.609344
Exact
Anything that goes on a claim form, a mileage log, or a tax return. Dividing keeps the one exact number instead of a truncated copy of it.
Which countries need the miles
IRS and HMRC publish their rates per mile, so a distance in kilometres has to be converted before those rules can be applied. CRA, ATO, IRD and SARS rates are already per kilometre.
| Country | Rate | Threshold | Tax year |
|---|---|---|---|
| United StatesIRS · Business mileage rate for employees and self-employed drivers. | 76 cents per mile | Business rate · 76 cents per mile | 2026 (Jul 1-Dec 31) |
| United KingdomHMRC · Cars and vans, for the employee's own vehicle. | 55 pence per mile, then 25 pence per mile | First 10,000 miles · 55 pence per mile; Over 10,000 miles · 25 pence per mile | 2026-27 |
| CanadaCRA · Automobile allowance benchmark; territories pay more. | 73 cents per kilometre, then 67 cents per kilometre | First 5,000 km · 73 cents per kilometre; After 5,000 km · 67 cents per kilometre | 2026 |
| AustraliaATO · All cars, work-related kilometres only. | 91 cents per kilometre | Cents per kilometre (up to 5,000 km) · 91 cents per kilometre | 2026-27 |
| New ZealandIRD · Petrol vehicle; diesel, hybrid and electric have their own rates. | 120 cents per kilometre, then 37 cents per kilometre | First 14,000 km · 120 cents per kilometre; After 14,000 km · 37 cents per kilometre | 2025-26 |
| South AfricaSARS · Simplified flat rate for business travel. | ZAR 4.95 per km | Simplified rate per km (up to 8,000 km) · ZAR 4.95 per km | 2026-27 |
Rates are read from the same catalog the calculators use, so a rate here cannot drift from the rate you get when you calculate.
Turning the converted distance into a claim figure
Two worked examples at the boundaries that matter, priced with the current published rate and the tier split applied.
HMRC · 2026-27
10,000 business miles in a UK tax year
£5,500.00
10,000 mi × 55 pence per mile = £5,500.00
The HMRC tier boundary. Below it the higher rate applies to every mile, so the split only matters once you cross it.
IRS · 2026 (Jul 1-Dec 31)
1,000 business miles in the United States
$760.00
1,000 mi × 76 cents per mile = $760.00
A single rate with no tier, which is why the US row needs no threshold and the converted miles figure is used as-is.
The calculator applies the tier split for you, and takes the distance in either unit.
Large kilometres in miles
The larger figures that come up when a year of driving has to be restated in miles.
50.00 km = 31.07 mi
A 50 km drive
31.07 mi, which is the figure an IRS or HMRC claim needs.
5,000 km = 3,106.86 mi
The CRA 5,000 km tier threshold
Canada pays a higher rate for the first 5,000 business kilometres. That threshold is 3,106.86 mi.
12,000 km = 7,456.45 mi
A 12,000 km driving year
A typical annual distance in a metric country, or about 7,456.45 mi.
20,000 km = 12,427.42 mi
20,000 km
A long-distance year, which comes to about 12,427.42 mi.
How to round a converted distance
The relationship is exact, so the only decision is how many decimals to keep. Round the converted figure for display, but keep the unrounded number until the multiplication is done — rounding the distance first and then applying a rate compounds the error.
Two decimals is enough for a mileage log: the remaining decimals are under 20 metres. On a long year of driving the difference is small, but it is not zero.
Round to whole units only when the figure is context rather than a claim — a 2,000 km drive is “about 1,243 miles” in a summary, but the claim should carry the decimal.
Kilometres to Miles: common questions
How many miles are in a kilometre?
One kilometre is about 0.621371 miles. The exact value is the reciprocal of 1.609344, so divide the kilometres by 1.609344 to get miles. Multiplying by a rounded 0.62 instead is out by about 0.0014 miles per kilometre.
How many kilometres are in a mile?
One mile is exactly 1.609344 kilometres, so a distance in kilometres is always the smaller number. Going the other way, multiply the miles by 1.609344.
How do I convert km to miles quickly without a calculator?
Multiply by 5 and divide by 8 for a fast estimate — equivalently, halve the kilometres and add an eighth of the original. That runs about 0.6% high. For a claim or a log, use the converter on this page instead: the difference is small per trip but adds up across a year.
Why do I need miles when the distance is already in kilometres?
Because IRS standard mileage rates and HMRC AMAP rates are published per mile, while CRA allowance rates and ATO cents per kilometre rates are published per kilometre. Converting the distance keeps the published rate intact, which is what a reviewer checks first.
Does a kilometer log need miles anywhere?
Only if you also claim under a per-mile rule. A Canadian or Australian log can stay in kilometres. If the same trip is claimed on an IRS or HMRC form, add the converted miles alongside the kilometre figure rather than replacing it.
How many miles is 100 km?
100 km is 62.14 miles. The exact factor is 0.621371 per kilometre, so 100 km is 100 divided by 1.609344.
How many miles is 5,000 km?
5,000 km is 3,106.86 miles. That figure matters in Canada, because the CRA pays 73 cents per kilometre for the first 5,000 business kilometres of a year and 67 cents after that.
Is a kilometre half a mile?
Not quite. A kilometre is 0.621371 miles, so it is a little over 62% of a mile, or about five eighths. Treating a kilometre as half a mile would understate a distance by roughly 20%, which is far too much error for a reimbursement figure.
How many miles is a marathon?
A marathon is 42.195 km, which is 26.22 miles — the familiar 26.2-mile figure is that value rounded. World Athletics gives the distance as 26 miles 385 yards, and it has been the standard since 1921.
Where these figures come from
States 1 mile = 1,609.344 metres, which is the 1.609344 km factor used throughout this page.
Gives the standard marathon distance as 26 miles 385 yards, or 42.195 km.
The conversion factor itself is arithmetic, not a published opinion: every figure on this page is computed from the mile definition above at render time.
Convert, measure, or price it
Measure a route if you need the driving distance rather than a unit change, then apply the rate for your country.
Converting the other direction?Miles to kilometers converter