How Many Millilitres in a Litre?
1,000, by definition. But a US cup isn't a UK cup, 1 mL of water weighs exactly 1 g (by design), and a "Nebuchadnezzar" of wine holds 20 standard bottles. Volume is where the metric system flexes hardest — and where cooking gets confusing fastest.
millilitres in a litre
The Multi-Unit Volume Converter
Type any volume in mL or litres. Get teaspoons, tablespoons, both US and UK fluid ounces, all three kinds of cup, pints, gallons — and the water-weight equivalent.
Equivalent in other units
The numbers behind the litre
The math, and the water trick
1 litre = 1,000 millilitres. The prefix milli- comes from the Latin mille, meaning one thousand. Same root as "million," "millennium," "millipede" (which has fewer than 1,000 legs, but the name aspires). A millilitre is, by definition, exactly one thousandth of a litre.
But the millilitre has another identity worth knowing: 1 mL = 1 cubic centimetre exactly. The two units are interchangeable. Medical "cc" (cubic centimetres) on an injection syringe is the same thing as a millilitre. This is also why a 10 cm × 10 cm × 10 cm box holds exactly 1 litre — that cube has 1,000 cm³ inside.
The cleanest part of metric volume is the relationship to water. 1 mL of water weighs exactly 1 gram at maximum density (4 °C). Extending: 1 litre of water = 1 kilogram. 1 cubic metre of water = 1 tonne. This isn't coincidence — when the metric system was being designed in 1795, the kilogram was defined as the mass of 1 cubic decimetre of pure water. The whole system was built around this single relationship. It's the reason metric is so clean: volume, mass and length all interlock through water.
Wine bottle sizes (named after biblical kings)
From the standard 750 mL up to a 30-litre Melchizedek — wine's most theatrical naming convention.
Wine bottle sizes above 1.5 litres are traditionally named after biblical kings, ancient rulers and legendary figures. The bigger the bottle, the better the wine ages (less surface area per volume) — and the more famous the namesake needs to be.
Bordeaux and Champagne disagree on a few names — Champagne uses "Methuselah" for the 6L bottle, while Bordeaux calls it "Imperial." The 15L Nebuchadnezzar is the largest size you'll typically find in a wine shop. Above that, bottles are special-orders for billionaires and Las Vegas nightclubs.
The cup is not the cup — recipe disasters explained
"1 cup" varies by 60 mL depending on where the recipe was written. The Japanese rice-cooker cup is its own thing entirely.
The gap between the smallest (Japanese, 180 mL) and the largest (UK Imperial, 284 mL) is 58%. A baker using a US cup to follow a UK recipe will under-measure by 20%; a UK baker using their grandmother's measuring cup against a modern Australian recipe will over-measure by 14%. This is why every serious baking blog now gives weights in grams alongside volumes.
Daily hydration calculator
The "8 glasses a day" rule is folk wisdom, not science. Real targets scale with body weight, activity and climate.
This is a baseline target including all sources (water, tea, food). About 20% of daily water typically comes from food. The "8 glasses a day" rule is rough — real needs scale with body mass, activity, climate and altitude. Roughly 30-35 mL per kg of body weight is a reasonable target for healthy adults.
Beverage volume reference
Common drink sizes worldwide — including where US and UK quietly disagree on the same name.
Volume scale reference
From a single eye drop (0.05 mL) to an Olympic pool (2.5 million litres). 10 orders of magnitude in 16 rows.
Volume, Wine & Water Quiz
Eight questions on litres, cups, biblical kings and what's actually inside you.
How many millilitres are in one litre?
Frequently Asked Questions
How many millilitres in a litre exactly?
Exactly 1,000. The prefix 'milli-' means one thousandth by definition (from Latin mille = 1,000). To convert L to mL, multiply by 1,000; for mL to L, divide by 1,000.
How many millilitres in half a litre?
500 mL. That's the volume of a standard single-serve water bottle worldwide. Other clean fractions: a quarter litre = 250 mL (= 1 metric cup), three-quarters = 750 mL (= a wine bottle), a tenth = 100 mL (= the TSA carry-on liquid limit).
How many millilitres in a litre of water?
1,000 mL, same as any litre — substance doesn't change volume. But 1 litre of water has the special property of weighing exactly 1 kilogram at 4°C. This isn't coincidence; the kilogram was defined in 1795 as the mass of 1 litre of pure water. The relationship is the foundation of the entire metric system.
Are 'cc' and 'mL' the same thing?
Yes, exactly — 1 cc (cubic centimetre) = 1 mL = 1 cm³ by definition. 'cc' is conventional in medicine (e.g., "10 cc injection"); 'mL' everywhere else. The 1879 redefinition of the litre as exactly 1 cubic decimetre (= 1,000 cm³) locked the two units together permanently.
How many ml in a standard water bottle?
The most common single-serve water bottle is 500 mL. Other common sizes: 330 mL (small / European), 600 mL (Australian standard), 750 mL (large / sports), 1 L (half-day bottle), 1.5 L and 2 L (large multi-serve). The TSA carry-on liquid limit is 100 mL per container.
How many litres of water should I drink a day?
The widely-used rule of thumb is 30-35 mL per kg of body weight, which works out to ~2.1-2.5 L for a 70 kg adult. About 20% of that typically comes from food. Hot climates and intense activity can push needs to 45+ mL/kg. Use the calculator above for a personalized estimate.
Sources
BIPM (Bureau International des Poids et Mesures). The SI Brochure, 9th edition (2019). Source for the relationship between the litre and the cubic decimetre, and the definition of metric prefixes including milli-.
NIST Special Publication 811. "Guide for the Use of the International System of Units (SI)." US National Institute of Standards and Technology — source for US customary vs US legal cup distinctions, US fluid ounce.
Weights and Measures Act 1985 (UK). Defines the Imperial pint (568.261 mL) and Imperial fluid ounce (28.4131 mL) still in legal use in the UK.
Sotheby's Wine & Christie's wine catalogue references. Standard names for large-format wine bottles, including the Bordeaux vs Champagne naming divergence at the 6L size (Imperial vs Methuselah).
Institute of Medicine (IOM), Dietary Reference Intakes for Water (2004). Source for hydration guidelines underlying the daily-water calculator. The 30-35 mL/kg baseline is consistent with IOM and European Food Safety Authority recommendations.
FINA (Fédération Internationale de Natation). Specification for an Olympic-size swimming pool: 50 m × 25 m × minimum 2 m depth, giving the 2,500 m³ (2.5 million litre) figure.
Related pages
Grams in a Kilogram
1,000 — plus your weight on Jupiter and the Le Grand K story.
Centimetres in a Metre
100 — and the dimensional jump from area to volume.
Kilometres in a Mile
1.609 — and the Fibonacci trick that approximates it.
Cups in a Litre
Depends which cup — between 3.5 and 5.6.
Ounces in a Pound
16 — and the weirdness of imperial weight.
Measurements hub →
Every length, weight and volume converter in one place.
1,000 is the easy answer. The honest one involves biblical kings, a 60 mL gap between national cups, and one quiet metric trick where water makes everything line up.