Volume Of Distribution Calculator

Work out volume of distribution instantly with clear inputs, formula shown and shareable results.

About Volume Of Distribution Calculator

Divides an intravenous dose by the extrapolated zero-time concentration to give the apparent volume of distribution.

Formula

Volume of distribution

Vd = dose / concentration at time zero; Vd per kg = Vd / body weight

Worked example

With the default values below, Volume Of Distribution Calculator returns Volume of distribution of 40.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Intravenous doseaccepts 0.1–100,000 mg: 500 mg
Extrapolated concentration at time zeroaccepts 0.01–1,000 mg/L: 12.5 mg/L
Body weightaccepts 1–250 kg: 70 kg

Results

Volume of distribution: 40.000 L
Volume of distribution per kilogram: 0.5714 L/kg
Distribution pattern: Distributed through extracellular water

Step by step

1Values used
2Volume of distribution
3Volume of distribution= 40.000 L
4Volume of distribution per kilogram= 0.5714 L/kg
5Distribution pattern= Distributed through extracellular water

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Why is it called apparent?

It is the volume that would be needed if the drug were evenly distributed at the plasma concentration, which is rarely physically true.

Can it exceed body volume?

Yes. Drugs that concentrate in tissue, such as digoxin or chloroquine, have volumes of hundreds of litres.