To convert light-years to hands, multiply by 9.311742591e+16. That factor is the whole relationship: both units measure length, so the conversion is a proportion with no offset and no substance-specific constant.
The distance light covers in one Julian year — about 9.46 trillion kilometres. 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". Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into hands, which is usually more useful than the bare number.
The formula
light-years- The amount you are converting, in light-years
9.31174259112e+16- The exact number of hands in one light-year
hands- The converted result
How it works, step by step
- Enter the value in light-years.
- It is multiplied by 9.31174259112e+16, 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
A larger figure: 100 ly in hands
A larger figure comes to about 100 ly. Multiplying by the factor: 100 × 9.31174e+16 = 9.31174e+18 hh. Dividing the answer back by 9.31174e+16 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
A round figure: 1 ly in hands
Take a round figure, roughly 1 ly. The conversion is a single multiplication — 1 × 9.31174e+16 — giving 9.31174e+16 hh. Because the relationship is proportional, doubling the input doubles the answer to 1.86235e+17 hh.
How to read your score
Frequently asked questions
How many hands are in one light-year?
Exactly 9.31174259112e+16. 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 light-years to hands?
hands = light-years × 9.31174259112e+16. Reversed, light-years = hands ÷ 9.31174259112e+16, which is the same as multiplying by 1.07391284737e-17.
Which is the bigger unit, the light-year or the hand?
The light-year. One light-year equals 9.31174e+16 hands.
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 light-year?
The distance light covers in one Julian year — about 9.46 trillion kilometres.
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 ly to hh in my head?
Plenty of people do this in their head: multiply by 9.0000e+16 instead of using the exact factor 9.3117e+16. At 100 that shortcut gives 9.0000e+18 hands, off by 3.1174e+17 hands or about 3.35%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Light-Years to hands reference tables
| Light-Years | Hands |
|---|---|
| 0.5 ly | 4.65587e+16 hh |
| 1 ly | 9.31174e+16 hh |
| 2 ly | 1.86235e+17 hh |
| 3 ly | 2.79352e+17 hh |
| 5 ly | 4.65587e+17 hh |
| 10 ly | 9.31174e+17 hh |
| 20 ly | 1.86235e+18 hh |
| 25 ly | 2.32794e+18 hh |
| 50 ly | 4.65587e+18 hh |
| 75 ly | 6.98381e+18 hh |
| 100 ly | 9.31174e+18 hh |
| 250 ly | 2.32794e+19 hh |
| 500 ly | 4.65587e+19 hh |
| 1000 ly | 9.31174e+19 hh |
| 5000 ly | 4.65587e+20 hh |
Exact factor: 1 light-year = 9.31174259112e+16 hands.
| Quantity | ly | hh |
|---|---|---|
| A credit card’s long edge | 9.048e-18 ly | 0.8425 hh |
| A door height | 2.148e-16 ly | 20 hh |
| An Olympic pool | 5.285e-15 ly | 492.1 hh |
| The Eiffel Tower | 3.488e-14 ly | 3248 hh |
| A marathon | 4.460e-12 ly | 4.153e+05 hh |
| Earth’s diameter | 1.347e-09 ly | 1.254e+08 hh |
Published reference values, converted with the same factor this page uses.