Flow rate measures how much fluid moves past a point in a given time, and it is central to plumbing, irrigation, pumps, ventilation and process engineering. The difficulty is that flow is quoted in many different units depending on the trade and the country. A pump curve might use cubic metres per hour, a tap might be rated in litres per minute, a scientific calculation might use cubic metres per second, and an American specification might list gallons per minute, while an air system might be given in cubic feet per minute. This converter takes a volumetric flow rate in any of these units and instantly shows the equivalent in all of the others, with a full reference list so you can read off whatever figure your work requires. Enter a value, choose the unit you are converting from, choose the unit you want, and the answer appears immediately. The method is straightforward and transparent. Every unit is defined as a number of cubic metres per second, the SI unit of volumetric flow, which acts as the base. The calculator multiplies your value by the factor for the from unit to reach cubic metres per second, then divides by the factor for the to unit. A handy check is that one litre per second equals exactly 60 litres per minute. Be aware that US and UK gallons are not the same size, so the two gallons-per-minute figures differ, and that this tool handles volume flow rather than mass flow, which would also need the fluid density. It suits plumbers, irrigation designers, engineers and students who need a quick, reliable flow conversion.
Each unit is defined by how many cubic metres per second it equals. To convert, the calculator multiplies your value by the factor for the unit you are converting from, which gives a value in cubic metres per second, then divides by the factor for the unit you want.
value in m³/s = value × factor[from]
result = value in m³/s / factor[to]
| Unit | Cubic metres per second per unit |
|---|---|
| Cubic metres per second (m³/s) | 1 |
| Litres per second (L/s) | 0.001 |
| Litres per minute (L/min) | 0.0000166666667 |
| Cubic metres per hour (m³/h) | 0.000277777778 |
| US gallons per minute (US GPM) | 0.0000630901964 |
| UK gallons per minute (UK GPM) | 0.0000757682 |
| Cubic feet per minute (CFM) | 0.000471947443 |
This converter is for plumbers, irrigation and HVAC designers, pump engineers and students who need to switch a flow rate between metric and imperial units when sizing pipes, pumps or ventilation.
Multiply by 60. One litre per second is 60 litres per minute.
A US gallon is about 3.785 litres and a UK gallon is about 4.546 litres, so the two figures differ for the same flow.
Cubic feet per minute, a flow rate common in ventilation. One CFM is about 28.3 litres per minute.
It converts volumetric flow. Mass flow would also need the density of the fluid.
If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.
Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.
All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.
Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.
Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.
Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.
All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.
About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use
Reviewed and maintained. Last reviewed 2026-06-07 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.
© 2026 Calculate.co.nz. All rights reserved. Building free NZ calculators since 2011.