About Grams and ml

Grams and ml is run by a single independent builder as eight free calculators built around one idea: a conversion between milliliters and grams, or milligrams and milliliters, has no fixed answer without a density or a concentration -- and every tool here makes that explicit, states the formula it runs, works a real example through with the tool's own defaults, and cites exactly where a density or concentration figure comes from.

How the calculators work

Every calculator on this site -- ml to grams, grams to ml, mg to ml, ml to mg, insulin units to ml, and the plain metric-prefix converters -- routes its math through one shared set of pure functions, rather than each tool re-implementing its own conversion logic. Every formula is checked against a hand-derived expected value in the site's own test suite before it ships.

Where the figures come from

Ingredient densities are derived from USDA FoodData Central household weights (USDA FoodData Central, SR Legacy (April 2018), food_portion.csv), never typed from memory -- see the Ingredient Density Table for every value and its exact food ID. The US cup and fluid-ounce volumes used to derive those densities are exact definitional values from NIST Handbook 44 (2018), Appendix C — General Tables of Units of Measurement, Units of Capacity or Volume - Liquid Volume Measure. Water's density is cited to Jones & Harris, "ITS-90 Density of Water Formulation for Volumetric Standards Calibration," NIST J. Res. 97, 335 (1992), Table 1. The insulin concentrations U-100 and U-40 are cited directly to FDA-approved product labeling (FDA-approved product labeling, Humulin® R (insulin human injection, USP), "100 UNITS PER ML (U-100)"; FDA Freedom of Information Summary, NADA 141-236 (Vetsulin®, porcine insulin zinc suspension), "40 international units (IU) insulin/mL"; "U-40 insulin syringe").

What it doesn't do

Nothing on this site is medical, dosing or pharmacist advice, and Grams and ml isn't affiliated with any pharmaceutical company, medical device maker, or the US Department of Agriculture or Food and Drug Administration. Every result depends on the density or concentration you enter or select, and real products vary by brand. Confirm any medicine amount against the actual product label and a pharmacist or prescriber before relying on it for a real decision. See Terms.

Every calculator

• ml to Grams Converter -- Convert milliliters to grams using a real ingredient density (water, milk, honey, flour and more) or your own custom density, with the math shown.
• Grams to ml Converter -- Convert grams to milliliters using a real ingredient density or a custom value you enter, with the formula and a worked example shown.
• mg to ml Calculator -- Convert milligrams to milliliters from a label concentration (mg per ml) or ingredient density -- label math only, not pharmacist advice.
• ml to mg Calculator -- Convert milliliters to milligrams from a label concentration (mg per ml) or ingredient density -- label math only, not pharmacist advice.
• Insulin Units to ml Calculator -- Convert insulin syringe units to milliliters using the U-100 or U-40 concentration on the vial label -- label math only, confirm with your care team.
• mcg to mg Converter -- Convert micrograms to milligrams instantly -- divide by 1,000 -- with a computed reference table at common values.
• mg to g Converter -- Convert milligrams to grams instantly -- divide by 1,000 -- with a computed reference table at common values.
• Ingredient Density Table -- Every ingredient density used on this site, sourced from USDA FoodData Central household weights, with the food ID and gram-per-cup figure.

Corrections

If a figure or citation here is wrong or out of date, email hello@gramsandml.com.