Approximate mg/L in water.
Parts per million water to Grams per Gallon Converter — ppm to g/gal
Convert Parts per million water (ppm) to Gram per Gallon (g/gal) using the exact conversion factor (1 parts per million water = 0.0037854118 gram per gallon). See the formula, worked examples, and conversion table.
Parts per million water to Grams per Gallon 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.
Mass concentration.
Result = input x 0.001 / 0.2641720524.
Mass Concentration units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Parts per million water to Grams per Gallon
Parts per million water and Gram per Gallon 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: Approximate mg/L in water, and mass concentration.
Formula
grams per gallon = parts per million water × 0.003785411784
This factor comes from each unit's defined relationship to the category's base unit: 1 parts per million water equals 0.001 base units, and 1 gram per gallon equals 0.264172052358 base units, so dividing one by the other gives the direct parts per million water-to-gram per gallon factor of 0.003785411784.
Simple example
1 ppm × 0.003785411784 = 0.0037854118 g/gal
1 parts per million water = 0.0037854118 grams per gallon.
Real-world example
100 ppm × 0.003785411784 = 0.3785411784 g/gal
100 parts per million water = 0.3785411784 grams per gallon.
Conversion table
| Parts per million water (ppm) | Gram per Gallon (g/gal) |
|---|---|
| 0.001 ppm | 0.0000037854 g/gal |
| 0.01 ppm | 0.0000378541 g/gal |
| 0.1 ppm | 0.0003785412 g/gal |
| 1 ppm | 0.0037854118 g/gal |
| 10 ppm | 0.0378541178 g/gal |
| 100 ppm | 0.3785411784 g/gal |
Reverse conversion: Gram per Gallon to Parts per million water
0.0037854118 g/gal × 264.1720524 = 1.000000004 ppm
0.0037854118 grams per gallon = 1.000000004 parts per million water.
parts per million water = grams per gallon × 264.172052358
For a page dedicated to this direction, see Gram per Gallon to Parts per million water.
Understanding the Parts per million water (ppm)
Approximate mg/L in water.
Understanding the Gram per Gallon (g/gal)
Mass concentration.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grams per gallon are in 1 parts per million water?
1 parts per million water equals 0.0037854118 grams per gallon, using the exact defined conversion factor rather than an estimate.
How do I convert parts per million water to gram per gallon?
Multiply the parts per million water value by 0.003785411784. The converter above does this instantly to whatever precision you set.
How do I convert gram per gallon back to parts per million water?
Use the reverse factor: 1 gram per gallon equals 264.1720524 parts per million water. You can also use the swap control in the converter above to flip the direction instantly.
What is a parts per million water?
Parts per million water (ppm) is a unit of chemistry.
What is a gram per gallon?
Gram per Gallon (g/gal) is a unit of chemistry.
Is the parts per million water to gram per gallon conversion exact?
Yes. Both parts per million water and gram per gallon are defined by fixed standards rather than physical artifacts, so the factor of 0.003785411784 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.