BIPM-ratified constants · v1.0

Converter

Pints, to litres (uk) converter calculator.

Convert UK imperial pints to litres and back using the legally exact factor of 0.56826125 litres per pint, as defined by the Weights and Measures Act 1985.

From

pints (uk)

pints_to_litres

1 pints_to_litres =0.56826Litres

Equivalents

Precision: 6 dp · Notation: Decimal · 2 units

→ Litres

Pints (UK)pints_to_litres0.56826

Litres → Pintslitres_to_pints1.7598

Common pairings

1 pints_to_litresequals1.7598 litres_to_pints

1 litres_to_pintsequals0.56826 pints_to_litres

The conversion

How the value
is computed.

UK Pints to Litres Conversion: Formula and Methodology

The UK imperial pint is a unit of volume defined under the Weights and Measures Act 1985, Schedule 1, as exactly 568.26125 millilitres (ml). Converting between UK pints and litres is a common requirement in cooking, the licensed trade, scientific measurement, and international commerce. This converter applies the legally exact conversion factor to deliver precise results in both directions.

The Conversion Formula

The standard formula for converting UK pints to litres is:

L = P × 0.56826125

Where the variables are defined as follows:

L — Volume expressed in litres (the output when converting from pints)
P — Volume expressed in UK imperial pints (the input value)
0.56826125 — The exact statutory conversion factor: litres per UK imperial pint

Derivation of the Conversion Factor

The factor 0.56826125 is not a rounded approximation — it is the exact legal conversion ratio. Since the UK imperial pint is defined as exactly 568.26125 ml under the Weights and Measures Act 1985, and one litre equals exactly 1,000 ml, the conversion factor follows directly: 568.26125 ÷ 1,000 = 0.56826125. This value aligns with international metrology standards maintained by the National Institute of Standards and Technology (NIST), which recognises the imperial pint at this exact volume.

Historical Background

The imperial pint has served as a standard British measure of volume since at least the 14th century. Its modern legal definition was consolidated in the Weights and Measures Act 1963 and reaffirmed by the 1985 Act. Although the UK adopted metric measurement for most commercial purposes following European harmonisation directives in the 1990s, the pint retained special legal status for sales of draught beer, draught cider, and milk sold in returnable containers.

Reverse Conversion: Litres to UK Pints

To convert litres to UK pints, divide the litre value by 0.56826125 or multiply by the reciprocal:

P = L ÷ 0.56826125 (equivalently: P = L × 1.75975398644)

For example, 3 litres ÷ 0.56826125 = approximately 5.279 UK pints.

Worked Examples

Example 1: 4 Pints to Litres (UK Milk Carton)

L = 4 × 0.56826125 = 2.273045 litres

A standard UK 4-pint milk carton holds approximately 2.27 litres.

Example 2: 1 Pint to Litres (Draught Beer)

L = 1 × 0.56826125 = 0.56826 litres (568.26 ml)

A UK pub pint is legally required to measure a full 568 ml, confirmed by the Weights and Measures Act 1985.

Example 3: 10 Pints to Litres

L = 10 × 0.56826125 = 5.6826125 litres

Quick Reference Conversion Table

0.5 pints = 0.284 litres
1 pint = 0.568 litres
2 pints = 1.137 litres
4 pints = 2.273 litres
6 pints = 3.410 litres
8 pints = 4.546 litres (equivalent to 1 UK gallon)
10 pints = 5.683 litres
20 pints = 11.365 litres

UK Pint vs. US Pint: A Critical Distinction

The US liquid pint equals only 473.176473 ml — approximately 16.65% smaller than the UK imperial pint of 568.26125 ml. Applying the US conversion factor (0.473176473 litres per pint) instead of the UK factor (0.56826125) creates an error of roughly 95 ml per pint. For a recipe calling for 4 pints, this error compounds to approximately 380 ml — nearly two thirds of a litre. As noted by The Open University guidance on converting units between measurement systems, confirming the correct regional standard before converting is essential for accuracy.

Practical Applications

Cooking and baking: Traditional British recipes frequently specify liquid volumes in pints; modern metric kitchen equipment requires conversion to millilitres or litres.
Licensed trade: Pub and bar operators may convert metric stock records for sales reported in pints under UK licensing regulations.
Medical fluid management: Healthcare settings occasionally cross-reference imperial and metric fluid volumes in patient intake and output records.
International trade and labelling: UK businesses exporting to EU markets must express product volumes in metric units, requiring accurate pint-to-litre conversion for compliance labelling.
DIY and automotive: Older UK vehicle manuals frequently specify coolant, oil, and fluid quantities in pints, requiring conversion for modern metric-marked containers.

Reference

Frequently asked questions

How many litres are in a UK pint?

One UK imperial pint equals exactly 0.56826125 litres, or 568.26125 millilitres. This precise value is defined by the Weights and Measures Act 1985, Schedule 1, and represents the legally binding standard for all imperial pint measurements in the United Kingdom. For most practical purposes, 1 UK pint is rounded to 0.568 litres or 568 ml.

What is the difference between a UK pint and a US pint in litres?

A UK imperial pint equals 0.56826125 litres (568.26 ml), while a US liquid pint equals only 0.473176473 litres (473.18 ml). The UK pint is therefore approximately 95 ml larger than the US pint — a difference of about 20%. Always confirm which pint definition applies before converting, as applying the wrong factor introduces a significant and compounding measurement error.

How do you convert litres back to UK pints?

To convert litres to UK pints, divide the litre value by 0.56826125, or multiply it by approximately 1.75975398644. For example, 2 litres divided by 0.56826125 equals approximately 3.52 UK pints. The reciprocal factor 1.75975398644 provides a direct multiplier for litres-to-pints calculations without requiring division, making it convenient for mental arithmetic and spreadsheet formulas.

Why does the UK still use pints instead of litres?

The UK retains the imperial pint for specific uses — particularly draught beer, draught cider, and milk sold in returnable containers — due to cultural tradition and legal exemptions within the Weights and Measures Act 1985 and subsequent statutory instruments. While the UK adopted metric units for most trade and commerce following European harmonisation directives, these specific categories were granted ongoing permission to use pint measures.

How many UK pints are in one litre?

One litre equals approximately 1.75975 UK imperial pints — the reciprocal of the conversion factor 0.56826125. In practical terms, a litre is very close to one and three-quarter pints. For example, a 1.5-litre bottle of water contains approximately 2.64 UK pints, and a standard 2-litre bottle contains approximately 3.52 UK pints.

Is the pints to litres conversion factor exact or an approximation?

The conversion factor of 0.56826125 litres per UK pint is exact, not an approximation. The UK imperial pint is defined in statute as exactly 568.26125 millilitres under the Weights and Measures Act 1985. Dividing this by 1,000 — the number of millilitres in one litre — yields the precise decimal factor 0.56826125, making any conversion using this figure accurate to the full number of decimal places shown.