To convert light-years to points, multiply by 2.681781866e+19. 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. The DTP point: exactly 1/72 inch, the unit type size is set in.
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 points so the number you get has something to be compared against.
The formula
light-years- The amount you are converting, in light-years
2.68178186624e+19- The exact number of points in one light-year
points- The converted result
How it works, step by step
- Enter the value in light-years.
- It is multiplied by 2.68178186624e+19, the exact factor between the two units.
- The answer is shown in points, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A round figure: 1 ly in points
At 1 ly (a round figure), the same quantity in points is 1 × 2.68178e+19 = 2.68178e+19 pt. One light-year is 2.68178e+19 points, so the numbers grow as expected.
A larger figure: 100 ly in points
Take a larger figure, roughly 100 ly. The conversion is a single multiplication — 100 × 2.68178e+19 — giving 2.68178e+21 pt. Because the relationship is proportional, doubling the input doubles the answer to 5.36356e+21 pt.
How to read your score
Frequently asked questions
How many points are in one light-year?
Exactly 2.68178186624e+19. 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 points?
points = light-years × 2.68178186624e+19. Reversed, light-years = points ÷ 2.68178186624e+19, which is the same as multiplying by 3.72886405336e-20.
Which is the bigger unit, the light-year or the point?
The light-year. One light-year equals 2.68178e+19 points.
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 point?
The DTP point: exactly 1/72 inch, the unit type size is set in.
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 pt in my head?
Plenty of people do this in their head: multiply by 2.7000e+19 instead of using the exact factor 2.6818e+19. At 100 that shortcut gives 2.7000e+21 points, off by 1.8218e+19 points or about 0.68%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Light-Years to points reference tables
| Light-Years | Points |
|---|---|
| 0.5 ly | 1.34089e+19 pt |
| 1 ly | 2.68178e+19 pt |
| 2 ly | 5.36356e+19 pt |
| 3 ly | 8.04535e+19 pt |
| 5 ly | 1.34089e+20 pt |
| 10 ly | 2.68178e+20 pt |
| 20 ly | 5.36356e+20 pt |
| 25 ly | 6.70445e+20 pt |
| 50 ly | 1.34089e+21 pt |
| 75 ly | 2.01134e+21 pt |
| 100 ly | 2.68178e+21 pt |
| 250 ly | 6.70445e+21 pt |
| 500 ly | 1.34089e+22 pt |
| 1000 ly | 2.68178e+22 pt |
| 5000 ly | 1.34089e+23 pt |
Exact factor: 1 light-year = 2.68178186624e+19 points.
| Quantity | ly | pt |
|---|---|---|
| A credit card’s long edge | 9.048e-18 ly | 242.6 pt |
| A door height | 2.148e-16 ly | 5760 pt |
| An Olympic pool | 5.285e-15 ly | 1.417e+05 pt |
| The Eiffel Tower | 3.488e-14 ly | 9.354e+05 pt |
| A marathon | 4.460e-12 ly | 1.196e+08 pt |
| Earth’s diameter | 1.347e-09 ly | 3.612e+10 pt |
Published reference values, converted with the same factor this page uses.