Number Converters · Browser · Free

PPM Converter

Enter a proportion in any one of the unit fields and press Convert to see it written in the others. Percent, permille, parts-per million, parts-per billion and parts-per trillion are all the same proportion on a different scale.

What the converter does

The form has six number fields: Decimal, Percent, Permille, Parts-per million, Parts-per billion and Parts-per trillion. Put a value in one of them and press Convert; nothing is worked out before you press the button.

The results appear in six cards below the button, each showing the same proportion in one of the units. Copy puts a result and its unit on the clipboard, and Clear resets the form so you can start again with a new figure.

For example, entering 10 in the Parts-per million field gives Decimal: 0.00001; Percent: 0.001 %; Permille: 0.01 ‰; Parts-per million: 10 ppm; Parts-per billion: 10000 ppb; Parts-per trillion: 10000000 ppt.

ppm conversion formula

Each unit is one proportion written on a different scale: percent counts parts per hundred, permille parts per thousand, parts-per million parts per million, parts-per billion parts per billion and parts-per trillion parts per trillion. The decimal field is that same proportion measured against a whole of one.

So one figure can be written several ways without changing its size. 10 ppm = 0.00001 = 0.001% = 10 ppm, and 5 % = 0.05 = 5% = 50000 ppm.

The larger units line up the same way: 10000 ppb = 0.00001 = 0.001% = 10 ppm and 10000000 ppt = 0.00001 = 0.001% = 10 ppm.

Reading the results

A small reading in parts per million is a very small proportion: entering Parts-per million: 10 returns Decimal: 0.00001; Percent: 0.001 %; Permille: 0.01 ‰; Parts-per million: 10 ppm; Parts-per billion: 10000 ppb; Parts-per trillion: 10000000 ppt. Working from the other side, entering Decimal: 0.001 returns Decimal: 0.001; Percent: 0.1 %; Permille: 1 ‰; Parts-per million: 1000 ppm; Parts-per billion: 1000000 ppb; Parts-per trillion: 1000000000 ppt.

Zero also converts across every unit: 0 ppm = 0 = 0% = 0 ppm, giving zero in all six result cards.

Everything is computed in the page itself, so the figures are ready as soon as you press Convert and nothing has to be sent away and back.