How the Hydraulic Fluid Converter Works
The Hydraulic Fluid Converter divides fluid mass by the density of the hydraulic fluid type. The default 0.875 kg/L fits ISO VG 46 mineral hydraulic oil.
Pick the fluid
Choose a mineral oil ISO VG grade or a fire-resistant or biodegradable fluid.
Enter the density
Use the table value; water-glycol fluids are heavier than water.
Enter the mass
Type the drum or reservoir fluid mass in kilograms.
Read the liters
Compare the result with the reservoir capacity.
Hydraulic Fluid Converter Formula
The hydraulic fluid formula is V = m ÷ ρfluid. Reservoirs are often sized at 3 times pump flow per minute.
- ρfluid
- Hydraulic fluid density at 15°C, kg/L
Worked Examples
- ISO VG 46 drum: 182 kg ÷ 0.875 = 208.0 L.
- Water-glycol HFC: 100 kg ÷ 1.07 = 93.46 L.
- Excavator reservoir 240 L: 240 × 0.875 = 210 kg of oil.
Hydraulic Fluid Converter Conversion Table
1 liter of ISO VG 46 hydraulic oil weighs about 0.875 kg. The table lists 8 hydraulic fluid types.
| Fluid Type | Density (kg/L) | Liters per 1 kg | 208 L drum (kg) | 20 L pail (kg) |
|---|---|---|---|---|
| ISO VG 22 mineral | 0.860 | 1.163 | 178.9 | 17.20 |
| ISO VG 32 mineral | 0.865 | 1.156 | 179.9 | 17.30 |
| ISO VG 46 mineral | 0.875 | 1.143 | 182.0 | 17.50 |
| ISO VG 68 mineral | 0.880 | 1.136 | 183.0 | 17.60 |
| ISO VG 100 mineral | 0.885 | 1.130 | 184.1 | 17.70 |
| HEES biodegradable ester | 0.920 | 1.087 | 191.4 | 18.40 |
| HFC water-glycol | 1.070 | 0.935 | 222.6 | 21.40 |
| HFDR phosphate ester | 1.150 | 0.870 | 239.2 | 23.00 |
What is a Hydraulic Fluid Converter?
A Hydraulic Fluid Converter is a calculator that converts hydraulic fluid weight into volume using the density of the fluid type.
Hydraulic fluids carry power through pumps, valves and cylinders. ISO 6743-4 classes mineral oils as HH, HL, HM and HV, and fire-resistant fluids as HFA to HFD.
ISO VG numbers give kinematic viscosity at 40°C in mm²/s. Higher VG grades flow thicker and weigh slightly more per liter.
What are the Uses of a Hydraulic Fluid Converter?
There are 4 main uses of a Hydraulic Fluid Converter.
Reservoir fills
Technicians convert drum weights into reservoir liters.
Fluid changeover
Plants plan flushing volumes when switching fluid types.
Machine shipping
Shippers add fluid mass to machine weights.
Leak tracking
Maintenance logs top-up kg as liters per month.