Quick answer: One inch is exactly 2.54 cm and one pound is 453.6 g. UK and US liquid measures are not the same: a UK pint is 568 ml and a US pint is 473 ml, while a UK fluid ounce (28.4 ml) is slightly smaller than a US fluid ounce (29.6 ml). To convert Fahrenheit to Celsius, subtract 32 and divide by 1.8.
Last updated: 12 November 2026
Product listings, recipes and instructions often mix metric, imperial and American units. These charts cover the conversions UK shoppers need most, with the exact factors where they exist. Figures are rounded for everyday use.
Length: inches, feet and centimetres
| Imperial | Metric |
|---|---|
| 1 inch (in) | 2.54 cm (exact) |
| 1 foot (ft) = 12 in | 30.48 cm |
| 1 yard (yd) = 3 ft | 0.9144 m (exact) |
| 1 mile = 1,760 yd | 1.609 km |
| 0.394 in | 1 cm |
| 3.281 ft (39.37 in) | 1 m |
| 0.621 miles | 1 km |
| Inches | Centimetres | Feet | Metres |
|---|---|---|---|
| 1 | 2.54 | 1 | 0.30 |
| 2 | 5.08 | 2 | 0.61 |
| 5 | 12.7 | 3 | 0.91 |
| 10 | 25.4 | 4 | 1.22 |
| 12 | 30.48 | 5 | 1.52 |
| 18 | 45.72 | 6 | 1.83 |
| 24 | 60.96 | 8 | 2.44 |
| 36 | 91.44 | 10 | 3.05 |
| 48 | 121.92 | 15 | 4.57 |
| 60 | 152.4 | 20 | 6.10 |
| 72 | 182.88 | 50 | 15.24 |
To convert inches to centimetres, multiply by 2.54. To convert feet to metres, multiply by 0.3048.
Weight: ounces, pounds, stones and kilograms
| Imperial | Metric |
|---|---|
| 1 ounce (oz) | 28.35 g |
| 1 pound (lb) = 16 oz | 453.6 g (0.4536 kg) |
| 1 stone = 14 lb | 6.35 kg |
| 3.53 oz | 100 g |
| 2.205 lb | 1 kg |
| Ounces | Grams | Pounds | Kilograms |
|---|---|---|---|
| 1 | 28 | 1 | 0.45 |
| 2 | 57 | 2 | 0.91 |
| 4 | 113 | 5 | 2.27 |
| 6 | 170 | 10 | 4.54 |
| 8 | 227 | 14 | 6.35 |
| 12 | 340 | 20 | 9.07 |
| 16 | 454 | 50 | 22.68 |
To convert ounces to grams, multiply by 28.35. To convert pounds to kilograms, multiply by 0.4536.
Volume: UK and US fluid ounces, pints, cups and gallons
The UK imperial system and the US customary system share names but not sizes. A UK pint has 20 fluid ounces and a US pint has 16, and the fluid ounces themselves differ slightly. Check which system a product or recipe uses.
| Unit | UK (imperial) | US |
|---|---|---|
| 1 fluid ounce (fl oz) | 28.41 ml | 29.57 ml |
| 1 pint | 568 ml (20 UK fl oz) | 473 ml (16 US fl oz) |
| 1 quart (2 pints) | 1.137 litres | 0.946 litres |
| 1 gallon (8 pints) | 4.546 litres | 3.785 litres |
| 1 cup | Not a standard UK unit; a metric cup is 250 ml | 237 ml (8 US fl oz) |
| 1 tablespoon | 15 ml (metric spoon) | 14.79 ml |
| 1 teaspoon | 5 ml (metric spoon) | 4.93 ml |
| US fluid ounces | Millilitres | UK fluid ounces | Millilitres |
|---|---|---|---|
| 1 | 30 | 1 | 28 |
| 2 | 59 | 2 | 57 |
| 4 | 118 | 4 | 114 |
| 8 | 237 | 8 | 227 |
| 12 | 355 | 12 | 341 |
| 16 | 473 | 16 | 455 |
| 20 | 591 | 20 | 568 |
| 32 | 946 | 32 | 909 |
| 64 | 1,893 | 64 | 1,818 |
| 128 | 3,785 | 128 | 3,637 |
US recipes measure many ingredients in cups; UK recipes usually weigh dry ingredients in grams. A US cup is about 237 ml.
Temperature and oven settings
°F = (°C × 1.8) + 32, and °C = (°F − 32) ÷ 1.8.
| °C | °F | Everyday reference |
|---|---|---|
| −18 | −0.4 | Typical freezer setting |
| 0 | 32 | Water freezes |
| 4 | 39.2 | Typical fridge setting |
| 20 | 68 | Comfortable room |
| 37 | 98.6 | Body temperature |
| 100 | 212 | Water boils |
| Gas mark | °C | °F | Description |
|---|---|---|---|
| ¼ | 110 | 225 | Very cool |
| ½ | 120 | 250 | Very cool |
| 1 | 140 | 275 | Cool |
| 2 | 150 | 300 | Cool |
| 3 | 170 | 325 | Moderate |
| 4 | 180 | 350 | Moderate |
| 5 | 190 | 375 | Moderately hot |
| 6 | 200 | 400 | Moderately hot |
| 7 | 220 | 425 | Hot |
| 8 | 230 | 450 | Hot |
| 9 | 240 | 475 | Very hot |
Oven temperatures are for conventional ovens and are rounded as recipes usually print them. For a fan oven, follow your oven's manual; recipes commonly suggest a lower setting.
Bed and mattress sizes: UK, Europe and US
Bedding sold online is not always made to UK sizes, so compare the measurements rather than the name.
| UK size | Centimetres | Feet and inches |
|---|---|---|
| Small single | 75 x 190 | 2'6" x 6'3" |
| Single | 90 x 190 | 3' x 6'3" |
| Small double | 120 x 190 | 4' x 6'3" |
| Double | 135 x 190 | 4'6" x 6'3" |
| King size | 150 x 200 | 5' x 6'6" |
| Super king | 180 x 200 | 6' x 6'6" |
| Elsewhere | Approximate centimetres | Closest UK size |
|---|---|---|
| European single | 90 x 200 | Single (10 cm longer) |
| European double | 140 x 200 | Double (5 cm wider, 10 cm longer) |
| European king | 160 x 200 | King size (10 cm wider) |
| European super king | 180 x 200 | Super king (same) |
| US twin | 97 x 190 | Single (7 cm wider) |
| US full | 137 x 190 | Double |
| US queen | 152 x 203 | King size |
| US king | 193 x 203 | Wider than a UK super king |
| US California king | 183 x 213 | Longer than a UK super king |
European and US sizes are typical figures and vary slightly by maker and country. Always check the dimensions in the product details.
Shoe sizes: UK, EU and US (adults)
UK and US sizes go up in steps of a third of an inch; EU sizes go up in steps of two-thirds of a centimetre. A US men's size is usually one higher than the UK size, and a US women's size about two higher.
| UK | EU | US men's | US women's |
|---|---|---|---|
| 3 | 35.5–36 | 4 | 5 |
| 4 | 37 | 5 | 6 |
| 5 | 38 | 6 | 7 |
| 6 | 39–39.5 | 7 | 8 |
| 7 | 40.5–41 | 8 | 9 |
| 8 | 42 | 9 | 10 |
| 9 | 43 | 10 | 11 |
| 10 | 44.5 | 11 | 12 |
| 11 | 45.5–46 | 12 | 13 |
| 12 | 47 | 13 | 14 |
This chart is approximate. Sizing differs between brands, so use the brand's own size guide or the foot length in centimetres where it is given.
Paper and envelope sizes
The UK uses the international A series, in which each size is half the one before. US Letter is slightly wider and shorter than A4.
| Size | Millimetres | Inches | Typical use |
|---|---|---|---|
| A3 | 297 x 420 | 11.7 x 16.5 | Posters, drawings |
| A4 | 210 x 297 | 8.3 x 11.7 | Standard UK printing and letters |
| A5 | 148 x 210 | 5.8 x 8.3 | Notebooks, flyers |
| A6 | 105 x 148 | 4.1 x 5.8 | Postcards |
| US Letter | 216 x 279 | 8.5 x 11 | Standard printing in the US |
| US Legal | 216 x 356 | 8.5 x 14 | US legal documents |
| DL envelope | 110 x 220 | 4.3 x 8.7 | A4 folded into thirds |
| C5 envelope | 162 x 229 | 6.4 x 9 | A4 folded in half (A5) |
| C4 envelope | 229 x 324 | 9 x 12.8 | A4 unfolded |
Electricity: voltage and plugs
| Region | Mains voltage | Frequency | Plug |
|---|---|---|---|
| United Kingdom | 230 V | 50 Hz | Three rectangular pins (BS 1363), fused |
| Most of Europe | 230 V | 50 Hz | Two round pins |
| USA and Canada | About 120 V | 60 Hz | Two flat pins, sometimes with a round earth pin |
A travel adaptor changes the shape of a plug but does not change the voltage. A product rated only for around 120 V is not suitable for UK mains; a label such as "INPUT: 100–240 V" means the product can be used on either supply. Buying electricals online explains plugs, fuses and safety marks.
Where these charts help
Bedding and cookware in Home & Kitchen; fixings and drill bits in DIY & Tools; planters and furniture in Garden & Outdoors; paper and envelopes in Stationery & Office; and footwear in Sports & Fitness. Comparing pack sizes? See Unit pricing explained. All twelve departments are on Shop by department.
Sources
- legislation.gov.uk: Weights and Measures Act 1985, Schedule 1 (definitions of units)
- NIST: Approximate conversions from U.S. customary measures to metric
- Bed Advice UK (National Bed Federation): UK bed and mattress size guide
- Electrical Safety First: Travel adaptors
- Electrical Safety First: Plugs and fuses
- Wikipedia: Gas mark (oven temperature table)
- Wikipedia: Bed size (European and North American sizes)
- Wikipedia: Shoe size (UK, US and Paris point systems)