Parts-Per Converter
- 50 x (1 x 10^-9) 5 x 10^-8 one
- 5 x 10^-8 / (1 x 10^-12) 50000 part per trillion
This page converts a parts-per ratio from one unit into another. Every value passes through the one, the SI unit parts-per ratio is held in, and parts-per ratio stays parts-per ratio: a unit only converts inside its own dimension.
How do you convert between ppm, ppb, ppt and percent?
Pick the unit you have, pick the unit you want, and type the value. The page multiplies by the factor between the two and prints the arithmetic under the result, so the answer and the working are the same object.
1 ppm is 1000 ppb and 1 % is 10 000 ppm. Each step down the list multiplies by a thousand: percent, parts per million, parts per billion, parts per trillion.
- Choose the unit your value is in. This page opens on the part per billion.
- Choose the unit you want it in. This page opens on the part per trillion.
- Type the value. The result and the factor behind it appear together.
- Read the working. It converts into the one first and out again, which is the same two lines you would write by hand.
Parts-Per Ratio Conversion Table
One row per unit this page offers, each measured against the one. The last column says whether the factor is a definition or a reading of one.
| Unit | Symbol | In the SI unit | Exact? |
|---|---|---|---|
| one | 1 | 1 | exact |
| percent | % | 0.01 | exact |
| per mille | per mille | 0.001 | exact |
| part per million | ppm | 0.000001 | exact |
| part per billion | ppb | 0.000000001 | exact |
| part per trillion | ppt | 0.000000000001 | exact |
Worked Examples
The question the bank ranked highest for this page, answered with the working.
What is 50 ppb in ppt?
- 50 x (1 x 10^-9) 5 x 10^-8 one
- 5 x 10^-8 / (1 x 10^-12) 50000 part per trillion
50 ppb = 50000 ppt
Where These Factors Come From
Every number above is read from the knowledge base rather than computed for the page. These are the statements it holds for parts-per ratio.
- Parts-per notation is a plain ratio: 1 % is one part in a hundred, 1 ppm is one part in a million, 1 ppb is one part in a billion and 1 ppt is one part in a trillion. So 1 ppm is 1000 ppb and 10 000 ppm is 1 %.
- How this page reports a result result in the target ratio unit; percent is written with the % sign, ppm/ppb/ppt in lower case
Is ppm by Mass or by Volume?
Either, and the basis has to be stated beside the figure. Parts-per notation is a plain ratio with no unit of its own, so this page can scale a value between percent and the parts-per units without knowing what is being counted.
The rule behind this factor is the same for every unit - why a conversion factor is a ratio equal to one.
Frequently Asked Questions
How do you convert ppb to ppt?
Multiply parts per billion by 1000.
How many ppm is 1 percent?
10 000 ppm.
Is ppm measured by mass or by volume?
Either, and the basis has to be stated. Parts-per notation is a plain ratio and carries no unit of its own.
How many ppb is 1 ppm?
1000 ppb.
Related Conversions
The rest of the family sits on the converter index for every quantity.