To convert millimeters to hands, multiply by 0.009842519685. That factor is the whole relationship: both units measure length, so the conversion is a proportion with no offset and no substance-specific constant.
One thousandth of a metre — the finest gradation on a standard ruler. Exactly four inches, and still the only accepted way to state the height of a horse.
The mil and the millimetre are not the same thing and are out by a factor of about forty. A mil is one thousandth of an inch — 0.0254 mm — and a spec sheet that quotes film thickness in mils means the small unit. British drawings write the same size as "thou". Below the calculator there is a step table for the values people look up most, and a second table putting real length figures into hands so the number you get has something to be compared against.
The formula
millimeters- The amount you are converting, in millimeters
0.00984251968504- The exact number of hands in one millimeter
hands- The converted result
How it works, step by step
- Enter the value in millimeters.
- It is multiplied by 0.00984251968504, the exact factor between the two units.
- The answer is shown in hands, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
An Olympic pool: 5e+04 mm in hands
An Olympic pool comes to about 5e+04 mm. Multiplying by the factor: 5e+04 × 0.00984252 = 492.126 hh. Dividing the answer back by 0.00984252 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
The Eiffel Tower: 3.3e+05 mm in hands
The Eiffel Tower comes to about 3.3e+05 mm. Multiplying by the factor: 3.3e+05 × 0.00984252 = 3248.03 hh. Dividing the answer back by 0.00984252 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
How to read your score
Frequently asked questions
How many hands are in one millimeter?
Exactly 0.00984251968504. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert millimeters to hands?
hands = millimeters × 0.00984251968504. Reversed, millimeters = hands ÷ 0.00984251968504, which is the same as multiplying by 101.6.
Which is the bigger unit, the millimeter or the hand?
The hand. One millimeter is only 0.00984252 of a hand, so it takes 101.6 millimeters to make one hand.
What does this quantity actually measure?
Both units measure length. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a millimeter?
One thousandth of a metre — the finest gradation on a standard ruler.
What is a hand?
Exactly four inches, and still the only accepted way to state the height of a horse.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do mm to hh in my head?
Plenty of people do this in their head: divide by 100 instead of using the exact factor 0.009842519685. At 100 that shortcut gives 1 hands, off by 0.01575 hands or about 1.60%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Millimeters to hands reference tables
| Millimeters | Hands |
|---|---|
| 0.5 mm | 0.00492126 hh |
| 1 mm | 0.00984252 hh |
| 2 mm | 0.019685 hh |
| 3 mm | 0.0295276 hh |
| 5 mm | 0.0492126 hh |
| 10 mm | 0.0984252 hh |
| 20 mm | 0.19685 hh |
| 25 mm | 0.246063 hh |
| 50 mm | 0.492126 hh |
| 75 mm | 0.738189 hh |
| 100 mm | 0.984252 hh |
| 250 mm | 2.46063 hh |
| 500 mm | 4.92126 hh |
| 1000 mm | 9.84252 hh |
| 5000 mm | 49.2126 hh |
Exact factor: 1 millimeter = 0.00984251968504 hands.
| Quantity | mm | hh |
|---|---|---|
| A credit card’s long edge | 85.6 mm | 0.8425 hh |
| A door height | 2032 mm | 20 hh |
| An Olympic pool | 5e+04 mm | 492.1 hh |
| The Eiffel Tower | 3.3e+05 mm | 3248 hh |
| A marathon | 4.22e+07 mm | 4.153e+05 hh |
| Earth’s diameter | 1.274e+10 mm | 1.254e+08 hh |
Published reference values, converted with the same factor this page uses.