Over the years the process of determining measurements (i.e. volume, capacity, weight, power, area, etc.) has become more complex with the variety of ways to calculate them.
Imperial (feet and inches) and Metric (mm, cm, metres and kilometres) are everyday examples of this. In many cases the size, bulk or speed of something may be measured using multiple methods. In different industries and businesses the method used may change by product, manufacturer, model, etc.
We hope you find the below conversion chart useful for all things related to your swimming pool or spa and the products you use on them. You may find them helpful when you are looking to size a replacement pump or pool cover, reviewing your pool heating requirements or calculating the right amount of chemicals to dose your pool with.
| Measurement | Convert to | Multiply by | Measurement | Convert to | Multiply by | |
| LENGTH | CAPACITY/VOLUME | |||||
| Micron | Metres | 0.0001 | Pounds of Water | Cubic Feet | 0.016 | |
| Inches | Millimetres | 25.4 | Cubic Feet of Water | Pounds | 62.72 | |
| Millimetres | Inches | 0.03937 | Gallons of Water | Pounds | 10 | |
| Inches | Centimetres | 2.54 | Pounds of Water | Gallons | 0.1 | |
| Feet | Metres | 0.30480 | Cubic Feet of Water | Gallons | 6.24 | |
| Metres | Feet | 3.2808 | Gallons of Water | Cubic Feet | 0.1602 | |
| Yards | Metres | 0.9144 | Cubic Metres of Water | Gallons | 220 | |
| Metres | Yards | 1.0936 | PRESSURE | |||
| Miles | Kilometres | 1.609 | Tons per Sq Inch | Kg per Sq Inch | 1.575 | |
| Milometres | Miles | 0.62137 | Kg per Sq Inch | Tons per Sq Inch | 0.635 | |
| AREA | POWER | |||||
| Sq Inches | Sq cm | 6.452 | HP | Watts | 746 | |
| Sq cm | Sq Inches | 0.155 | Watts | HP | 0.00134 | |
| Sq Metres | Sq Feet | 10.764 | Kw | BTU | 3412 | |
| Sq Feet | Sq Metres | 0.0929 | BTU | Kw | 0.000293 | |
| Sq Yards | Sq Metres | 0.8361 | ||||
| Sq Metres | Sq Yards | 1.19599 | PUMP CONVERSATION VALUES | |||
| Sq Metres | Acres | 0.000247 | 0.5HP | 3 amps | 0.375kW | |
| Acres | Sq Metres | 4046.86 | 0.75HP | 5 amps | 0.560kW | |
| Hectare | Sq Metres | 10,000 | 1.0HP | 6 amps | 0.750kW | |
| Acre | Hectare | 0.4047 | 1.5HP | 7 amps | 1.120kW | |
| Hectare | Acre | 2.471 | 2.0HP | 10 amps | 1.500kW | |
| WEIGHT/MASS | POOL CAPACITY/VOLUME | |||||
| Ounces | Grammes | 28.3495 | Square or Rectangle | |||
| Grammes | Ounces | 0.03527 | Imperial – Capacity | L x W x AvD x 6.25 | = Gallons | |
| Pounds | Ounces | 453.59237 | Metric – Capacity | L x W x AvD x 1.0m³ | = m³ | |
| Grammes | Pounds | 0.0022046 | Round or Oval | |||
| Pounds | Kilogrammes | 0.45359 | Imperial – Capacity | Ø x Ø x AvD x 4.90 | = Gallons | |
| Kilogrammes | Pounds | 2.20462 | Metric – Capacity | Ø x Ø x AvD x 0.80m³ | = m³ | |
| CWT | Kilogrammes | 50.8 | ||||
| Kilogrammes | CWT | 0.01968 | MAX PIPE FLOW RATES | Suction | Return | |
| Tons | Kilogrammes | 1016.05 | 1.00″ Class C | 14 GPM | 23 GPM | |
| 1.50″ Class C | 34 GPM | 57 GPM | ||||
| CAPACITY/VOLUME | 2.00″ Class C | 54 GPM | 90 GPM | |||
| Cubic Inches | Cubic cm | 16.387 | ||||
| Cubic cm | Cubic Inches | 0.06102 | PRODUCT WEIGHTS/COVERAGE | |||
| Cubic Feet | Cubic Metres | 0.0283 | 25kg Marbaline Covers | approx 2m² x 6mm thick | ||
| Cubic Metres | Cubic Feet | 35.3147 | 22kg Adhesive will cover | approx 9.29m² | ||
| Cubic Yards | Cubic Metres | 0.76 | 2.5kg Grout will cover | approx 1.86m² | ||
| Cubic Metres | Cubic Yards | 1.30795 | 30 sheets of Mosaic per box | 23kg weight | ||
| Pints | Fluid Ounces | 20 | 5ltr Chlorinated rubber paint covers | approx 30m² | ||
| Pints | Litres | 0.568 | 5ltr water based paint covers | approx 40m² | ||
| Litres | Pints | 1.761 | 200×610mm straight coping | 15kg weight | ||
| Gallons | Litres | 4.546 | 305×610mm straight coping | 22kg weight | ||
| Litres | Gallons | 0.22 | 200×457mm flat top coping | 16kg weight | ||
| UK Gallons | US Gallons | 1.20095 | ||||
| US Gallons | UK Gallons | 0.832674 | ||||
| Cubic Inches | Litres | 0.01639 | ||||
| Litres | Cubic Inches | 61.013 |
Paul Woodhead
Gary Woods