Expert Verified Flow Rate Analysis Updated 2026

m³/hr to kg/hr Calculator

Convert volumetric flow rate in cubic meters per hour (m³/hr) to mass flow rate in kilograms per hour (kg/hr) using fluid density. Supports water, diesel, gasoline, and custom density inputs. Free, fast, and technically verified.

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× VOLUME (m³/hr) MASS (kg/hr) DENSITY (kg/m³) FLOW RATE CONVERTER
Density-Based Conversion
Supports Multiple Fluids
Custom Density Input
Instant Mass Flow Calculation

m3 hr to kg hr Calculator

Mass Flow Rate (kg/hr)
0 kg/h

Technical Note: Volumetric flow rate (m³/hr) represents the physical volume of fluid passing per unit time, while mass flow rate (kg/hr) represents the actual mass. Volumetric flow rate cannot be converted to mass flow rate without knowing the fluid density (kg/m³), as fluids with equal volumes can have significantly different masses.

Formula: kg/hr = m³/hr × density (kg/m³)

How to Use m3 hr to kg hr Calculator

Converting volumetric flow rate values from cubic meters per hour (m³/hr) to mass flow rate in kilograms per hour (kg/hr) is a common requirement in pump system sizing, pipeline analysis, and fluid processing. Since volumetric flow does not account for the weight of the fluid, you must incorporate density. Follow these steps to perform the conversion:

  1. 1. Enter volumetric flow: Input the flow rate value in cubic meters per hour (m³/hr) into the volumetric flow rate input field.
  2. 2. Select fluid type: Click the fluid type dropdown menu and choose from standard fluids like water, diesel, gasoline, milk, or sea water.
  3. 3. Enter density if custom fluid is used: If your specific fluid is not listed, select Custom Density from the dropdown and type its density in kilograms per cubic meter (kg/m³).
  4. 4. Click Calculate: Press the Calculate button to trigger the mathematical conversion.
  5. 5. Read the resulting mass flow rate: Review the calculated mass flow rate in kilograms per hour (kg/hr) displayed in the main output card and review the details container.

How to Calculate m3 hr to kg hr

To convert volumetric flow rate to mass flow rate, you multiply the volumetric flow by the density of the fluid. The physical conversion depends directly on temperature and pressure, which dictate the fluid's density. Ensure all units are compatible prior to calculation.

Formula:

kg/hr = m³/hr × density (kg/m³)

Where:

  • kg/hr = Mass flow rate in kilograms per hour
  • m³/hr = Volumetric flow rate in cubic meters per hour
  • density (kg/m³) = Mass density of the fluid in kilograms per cubic meter

Verified Real-Life Scenario 1 (Water)

Consider a pump system circulating freshwater at a volumetric rate of 10 m³/hr. Water has a density of 1000 kg/m³ under standard conditions.

Step-by-step calculations:

kg/hr = 10 × 1000
kg/hr = 10,000 kg/hr

Final answer:

A volumetric flow rate of 10 m³/hr of water equals a mass flow rate of 10,000 kg/hr.

Verified Real-Life Scenario 2 (Diesel)

Now consider a fuel pipeline transferring diesel at a rate of 20 m³/hr. Diesel has a density of 850 kg/m³.

Step-by-step calculations:

kg/hr = 20 × 850
kg/hr = 17,000 kg/hr

Final answer:

A volumetric flow rate of 20 m³/hr of diesel equals a mass flow rate of 17,000 kg/hr.

m3 hr to kg hr Chart

This table lists volumetric flow rate conversions from cubic meters per hour (m³/hr) to kilograms per hour (kg/hr) based on freshwater density of 1000 kg/m³. If you are using a different fluid, the mass flow rate will vary based on the specific gravity of that substance.

Volumetric Flow Rate (m³/hr) Fluid Density (kg/m³) Mass Flow Rate (kg/hr)
1 m³/hr 1000 1,000 kg/hr
2 m³/hr 1000 2,000 kg/hr
5 m³/hr 1000 5,000 kg/hr
10 m³/hr 1000 10,000 kg/hr
15 m³/hr 1000 15,000 kg/hr
20 m³/hr 1000 20,000 kg/hr
25 m³/hr 1000 25,000 kg/hr
50 m³/hr 1000 50,000 kg/hr
75 m³/hr 1000 75,000 kg/hr
100 m³/hr 1000 100,000 kg/hr

Note: Volumetric flow conversions to mass flow change proportionally with fluid density. For fluids other than water, multiply the volumetric flow by the fluid's specific density to find the correct mass flow.

m3 hr to kg hr Frequently Asked Questions

To convert volumetric flow in cubic meters per hour (m³/hr) to mass flow in kilograms per hour (kg/hr), multiply the flow rate by the fluid density in kilograms per cubic meter (kg/m³). The calculation is represented by the formula: kg/hr = m³/hr × density.

No, cubic meters per hour measures volumetric flow, whereas kilograms per hour measures mass flow. Because mass depends on how tightly molecules are packed within a given volume, you cannot convert between them without knowing the specific density of the fluid under current operating temperatures.

Density defines the mass of a substance per unit volume. Different fluids have distinct densities; for example, a cubic meter of water weighs 1000 kilograms, while the same volume of gasoline weighs only 740 kilograms. Density serves as the conversion factor to bridge volume and mass.

Under standard conditions at 4 degrees Celsius, freshwater has a density of approximately 1000 kilograms per cubic meter (kg/m³). This value decreases slightly as temperature rises. For standard engineering calculations, 1000 kg/m³ is the widely accepted default density for water.

The physical formula is: mass flow rate (kg/hr) = volumetric flow rate (m³/hr) × fluid density (kg/m³). This formula assumes the density is specified in standard metric units and represents the specific state of the fluid at the point of measurement.

Yes, fluids expand or contract with temperature changes, which directly alters their density. When temperature increases, fluid density generally decreases, meaning a set volume will weigh less. For high-precision mass flow calculations, density should be adjusted for temperature.

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