How the Distilled Water Converter Works
The Distilled Water Converter uses the density of pure, ion-free water at the selected temperature. The default 0.9982 kg/L matches distilled water at 20°C (68°F), the reference for lab glassware.
Check the water temperature
Read the temperature of the distilled or deionized (DI) water.
Enter the matching density
Use 0.99820 kg/L at 20°C, 0.99705 kg/L at 25°C, or a value from a water density table.
Enter the weighed mass
Type the net mass in kilograms (grams ÷ 1,000).
Read the true volume
The result gives the volume to four decimals for gravimetric checks.
Distilled Water Converter Formula
The distilled water formula is V = m ÷ ρDI(T), with ρDI = 0.99820 kg/L at 20°C.
- ρDI(T)
- Density of distilled water at temperature T
- Z
- Conversion factor in mL/g including air buoyancy (1.0029 at 20°C)
Worked Examples
- 1 kg at 20°C: 1 ÷ 0.9982 = 1.0018 L (1,001.8 mL).
- Pipette check: 9.982 g of distilled water at 20°C equals 10.000 mL before air-buoyancy correction.
- Z-factor method: 99.71 g read on a balance × 1.0029 mL/g = 100.00 mL.
Distilled Water Converter Conversion Table
100 mL of distilled water weighs 99.820 g at 20°C and 99.705 g at 25°C. The table lists the mass of distilled water that fills common lab glassware.
| Glassware Volume | Mass at 15°C (g) | Mass at 20°C (g) | Mass at 25°C (g) | Mass at 30°C (g) |
|---|---|---|---|---|
| 1 mL | 0.999 | 0.998 | 0.997 | 0.996 |
| 2 mL | 1.998 | 1.996 | 1.994 | 1.991 |
| 5 mL | 4.996 | 4.991 | 4.985 | 4.978 |
| 10 mL | 9.991 | 9.982 | 9.971 | 9.957 |
| 25 mL | 24.978 | 24.955 | 24.926 | 24.891 |
| 50 mL | 49.955 | 49.910 | 49.853 | 49.783 |
| 100 mL | 99.910 | 99.820 | 99.705 | 99.565 |
| 250 mL | 249.775 | 249.550 | 249.263 | 248.913 |
| 500 mL | 499.550 | 499.100 | 498.525 | 497.825 |
| 1,000 mL | 999.100 | 998.200 | 997.050 | 995.650 |
| 2,000 mL | 1,998.200 | 1,996.400 | 1,994.100 | 1,991.300 |
True mass in vacuum. A balance reading in air sits about 0.1% lower; the ISO 4787 Z-factor corrects for that buoyancy.
What is a Distilled Water Converter?
A Distilled Water Converter is a calculator that converts the mass of distilled or deionized water into volume using laboratory-grade water density.
Distilled water contains no dissolved minerals, so its density follows the reference curve published by NIST and the IAPWS. Tap water carries 50–500 mg/L of dissolved solids, which adds up to 0.05% to its density.
Labs use distilled water to calibrate pipettes, burettes and volumetric flasks by weight. The method, called gravimetric calibration, is set out in ISO 4787 and ISO 8655.
What are the Uses of a Distilled Water Converter?
There are 4 main uses of a Distilled Water Converter.
Pipette calibration
Labs weigh dispensed water to verify pipette accuracy under ISO 8655.
Flask verification
Technicians confirm volumetric flask marks by weight.
Battery top-up
Workshops measure distilled water for lead-acid battery cells.
Steam irons and CPAP machines
Users convert bulk distilled water purchases into fills.