Milliliters to Congii (mL to congius)

1 milliliter equals 0.0003053435115 congii (rounded).

1 milliliter = 0.0003053435115 congii

How to convert milliliters to congii

To convert milliliters to congii, multiply the number of milliliters by 0.0003053435115. The factor is rounded to 10 significant digits. To go the other way, multiply congii by 3,275.

congii = milliliters × 0.0003053435115

Example: 10 milliliters = 0.003053435115 congii.

Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.

Approximate value. Standards for the congius varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About these units

Milliliter (mL)

Metric (SI)Current unit

One thousandth of a liter, or exactly 1 cubic centimeter. Used for medicine, cooking and small containers.

Milliliters inherit everything from the liter, since the prefix simply means one thousandth. Because the liter is a cubic decimeter, a milliliter works out to exactly one cubic centimeter, a coincidence the metric system built in on purpose so that volume, length and mass interlock. One milliliter of water has a mass of about one gram, so a dosing syringe, a kitchen scale and a measuring jug can all be checked against one another.

Today milliliters dominate wherever small amounts must be measured precisely: medicine, flavorings, perfume, shampoo and the fine print on drink labels. Spelling is a mild regional split, with uppercase mL preferred in the United States, Canada and Australia and lowercase ml common in the UK and Europe. For scale, a US teaspoon is just under 5 mL, a US tablespoon is about 14.8 mL, and the US nutrition-label cup is exactly 240 mL, so one such cup is 240 of these tiny units.

1 milliliter = 0.001 liters (exactly).

Sources: Wikipedia: Litre; NIST SP 811, Appendix B.8: conversion factors for volume; 21 CFR 101.9: nutrition labeling household measures

Congius (congius)

Ancient RomanHistorical unit (no longer in standard use)Approximate value

Six sextarii, about 3.27 L. A Roman liquid measure a little under a US gallon.

Eight congii made up one amphora quadrantal, and each congius was defined as a cube measuring half a Roman foot on each side. Wikipedia's table gives it as 3.27 L, which is the figure used here. The cube definition links it directly to the length standard, so any doubt about the exact length of the pes carries straight into the volume.

Inside the liquid scale, the congius was divided into 6 sextarii, and further down into 72 cyathi. Larger vessels such as the culeus were counted in congii, with 160 of them to the culeus. Because it came to roughly 3.3 L, it sits near the modern US gallon of 3.785 L, though it is noticeably smaller. Surviving vessels never match each other exactly, and the sextarii they imply range between 500 and 580 mL, so a congius from archaeology could fall anywhere from about 3.0 to 3.5 L.

1 congius = 3.275 liters (approximately).

Sources: Wikipedia: Ancient Roman units of measurement

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