One millimeter is exactly 1,000,000,000 picometers, so converting millimeters to picometers is a single multiplication. Enter any figure and the result appears as you type — the arithmetic runs in your browser, so nothing is sent anywhere.
One trillionth of a metre, the SI unit crystallographers use where chemists still reach for angstroms. One thousandth of a metre — the finest gradation on a standard ruler.
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 picometers so the number you get has something to be compared against.
The formula
millimeters- The amount you are converting, in millimeters
1,000,000,000- The exact number of picometers in one millimeter
picometers- The converted result
How it works, step by step
- Enter the value in millimeters.
- It is multiplied by 1,000,000,000, the exact factor between the two units.
- The answer is shown in picometers, 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 picometers
An Olympic pool comes to about 5e+04 mm. Multiplying by the factor: 5e+04 × 1e+09 = 5e+13 pm. Dividing the answer back by 1e+09 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 picometers
The Eiffel Tower comes to about 3.3e+05 mm. Multiplying by the factor: 3.3e+05 × 1e+09 = 3.3e+14 pm. Dividing the answer back by 1e+09 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 picometers are in one millimeter?
Exactly 1,000,000,000. 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 picometers?
picometers = millimeters × 1,000,000,000. Reversed, millimeters = picometers ÷ 1,000,000,000, which is the same as multiplying by 1e-09.
Which is the bigger unit, the millimeter or the picometer?
The millimeter. One millimeter equals 1e+09 picometers.
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 picometer?
One trillionth of a metre, the SI unit crystallographers use where chemists still reach for angstroms.
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.
Millimeters to picometers reference tables
| Millimeters | Picometers |
|---|---|
| 0.5 mm | 5e+08 pm |
| 1 mm | 1e+09 pm |
| 2 mm | 2e+09 pm |
| 3 mm | 3e+09 pm |
| 5 mm | 5e+09 pm |
| 10 mm | 1e+10 pm |
| 20 mm | 2e+10 pm |
| 25 mm | 2.5e+10 pm |
| 50 mm | 5e+10 pm |
| 75 mm | 7.5e+10 pm |
| 100 mm | 1e+11 pm |
| 250 mm | 2.5e+11 pm |
| 500 mm | 5e+11 pm |
| 1000 mm | 1e+12 pm |
| 5000 mm | 5e+12 pm |
Exact factor: 1 millimeter = 1,000,000,000 picometers.
| Quantity | mm | pm |
|---|---|---|
| A credit card’s long edge | 85.6 mm | 8.56e+10 pm |
| A door height | 2032 mm | 2.032e+12 pm |
| An Olympic pool | 5e+04 mm | 5e+13 pm |
| The Eiffel Tower | 3.3e+05 mm | 3.3e+14 pm |
| A marathon | 4.22e+07 mm | 4.220e+16 pm |
| Earth’s diameter | 1.274e+10 mm | 1.274e+19 pm |
Published reference values, converted with the same factor this page uses.