Mass concentration.
Milligrams per Gallon to Parts per million water Converter — mg/gal to ppm
Convert Milligram per Gallon (mg/gal) to Parts per million water (ppm) using the exact conversion factor (1 milligram per gallon = 0.2641720524 parts per million water). See the formula, worked examples, and conversion table.
Milligrams per Gallon to Parts per million water converter
Converter
Chemistry Converter
Convert concentration, molarity, amount, and laboratory scientific units by compatible family.
Context values
Some unit families need one extra value for a physically accurate result.
Approximate mg/L in water.
Result = input x 0.0002641720524 / 0.001.
Mass Concentration units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Milligrams per Gallon to Parts per million water
Milligram per Gallon and Parts per million water both measure mass concentration — how much of a substance is dissolved or dispersed in a given volume — a core calculation for preparing lab solutions, checking water quality against a regulatory limit, or formulating a pharmaceutical dose. Specifically: Mass concentration, and approximate mg/L in water.
Formula
parts per million water = milligrams per gallon × 0.264172052358
This factor comes from each unit's defined relationship to the category's base unit: 1 milligram per gallon equals 0.000264172052358 base units, and 1 parts per million water equals 0.001 base units, so dividing one by the other gives the direct milligram per gallon-to-parts per million water factor of 0.264172052358.
Simple example
1 mg/gal × 0.2641720524 = 0.2641720524 ppm
1 milligram per gallon = 0.2641720524 parts per million water.
Real-world example
100 mg/gal × 0.2641720524 = 26.41720524 ppm
100 milligrams per gallon = 26.41720524 parts per million water.
Conversion table
| Milligram per Gallon (mg/gal) | Parts per million water (ppm) |
|---|---|
| 0.001 mg/gal | 0.0002641721 ppm |
| 0.01 mg/gal | 0.0026417205 ppm |
| 0.1 mg/gal | 0.0264172052 ppm |
| 1 mg/gal | 0.2641720524 ppm |
| 10 mg/gal | 2.641720524 ppm |
| 100 mg/gal | 26.41720524 ppm |
Reverse conversion: Parts per million water to Milligram per Gallon
0.2641720524 ppm × 3.785411784 = 1 mg/gal
0.2641720524 parts per million water = 1 milligrams per gallon.
milligrams per gallon = parts per million water × 3.785411784
For a page dedicated to this direction, see Parts per million water to Milligram per Gallon.
Understanding the Milligram per Gallon (mg/gal)
Mass concentration.
Understanding the Parts per million water (ppm)
Approximate mg/L in water.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many parts per million water are in 1 milligram per gallon?
1 milligram per gallon equals 0.2641720524 parts per million water, using the exact defined conversion factor rather than an estimate.
How do I convert milligram per gallon to parts per million water?
Multiply the milligram per gallon value by 0.2641720524. The converter above does this instantly to whatever precision you set.
How do I convert parts per million water back to milligram per gallon?
Use the reverse factor: 1 parts per million water equals 3.785411784 milligrams per gallon. You can also use the swap control in the converter above to flip the direction instantly.
What is a milligram per gallon?
Milligram per Gallon (mg/gal) is a unit of chemistry.
What is a parts per million water?
Parts per million water (ppm) is a unit of chemistry.
Is the milligram per gallon to parts per million water conversion exact?
Yes. Both milligram per gallon and parts per million water are defined by fixed standards rather than physical artifacts, so the factor of 0.2641720524 used above is exact to as many digits as you choose to display.
What's the difference between mass concentration and molarity?
Mass concentration expresses how much mass of a substance is present per unit volume (for example, grams per liter). Molarity expresses the amount in moles per liter instead, which accounts for the substance's molecular weight. This category converts mass-concentration units.