Density Calculator for Mass, Volume, and Density
This density calculator solves the density formula ρ = m / V for whichever value you are missing. Enter any two of density, mass, and volume, and the third is worked out instantly in the unit you choose.
It is built for students, lab work, and everyday checks alike: identify an unknown material, find the mass of a known volume, or see how much space a given mass takes up. A live comparison chart even shows whether your result would sink or float in water.
How to Calculate Density
Enter two known values
Type values into any two of the three cards — Density (ρ), Mass (m), and Volume (V). The third card fills in automatically as you type.
Pick your units
Each card has its own unit dropdown, so you can mix systems — for example, mass in pounds and volume in liters. All conversions are handled for you.
Tune the precision
Set the Decimals control to 2, 3, 4, or 6 places to match the accuracy you need. The default is 4 decimals.
Read the result
See the calculated value, the formula used with your numbers, a full unit-conversion table, and a density comparison against common materials with a sink/float note.
Want a head start? Click Examples to load a ready-made calculation such as water, a steel block, or a gold bar, then press Reset to clear the cards and begin again.
Features
Solve Any Variable
Enter any two of density, mass, and volume, and the tool solves the third using ρ = m/V, m = ρ × V, or V = m/ρ.
8 Density Units
Choose from kg/m³, g/cm³, g/mL, kg/L, lb/ft³, lb/in³, oz/in³, and slug/ft³.
7 Mass Units
Work in mg, g, kg, tonnes (t), pounds (lb), ounces (oz), or slugs, with conversions handled automatically.
8 Volume Units
Enter volume as mm³, cm³, mL, L, m³, gallons, ft³, or in³ and mix freely with any mass unit.
Real-Time Results
The answer updates the moment you type or change a unit — there is no calculate button to press.
Unit Conversion Table
Expand the table to see your result expressed in every available unit at once, so you never have to convert by hand.
Material Comparison Chart
A visual bar chart places your density among 12 common materials, from air (1.225 kg/m³) to gold (19,300 kg/m³).
Sink or Float Indicator
Each result is compared to water (1,000 kg/m³) with a clear note on whether the material would sink, float, or stay neutral.
Adjustable Precision
Control the number of decimal places — 2, 3, 4, or 6 — to suit anything from quick estimates to lab-grade figures.
Quick Examples & Reference
Load six preset scenarios with one click, and open the all-formulas reference table for ρ, m, and V at any time.
Frequently Asked Questions
What is the formula for density?
Density is calculated with ρ = m / V, where ρ (rho) is density, m is mass, and V is volume. The same relationship rearranges to find mass (m = ρ × V) or volume (V = m / ρ), and this calculator handles all three.
How do I calculate density from mass and volume?
Enter the mass in the Mass card and the volume in the Volume card, each with its own unit. The Density card fills in immediately, dividing mass by volume. You can switch the density unit afterward to read the result in kg/m³, g/cm³, and more.
What units does this calculator support?
It supports 8 density units (kg/m³, g/cm³, g/mL, kg/L, lb/ft³, lb/in³, oz/in³, slug/ft³), 7 mass units (mg, g, kg, t, lb, oz, slug), and 8 volume units (mm³, cm³, mL, L, m³, gal, ft³, in³). You can mix units across cards freely.
How do I find mass or volume if I already know the density?
Enter the density plus the one value you know. To find mass, fill in Density and Volume; to find volume, fill in Density and Mass. The remaining card is calculated automatically using m = ρ × V or V = m / ρ.
How does the sink or float indicator work?
Water has a density of 1,000 kg/m³. Materials below that value float and materials above it sink. Whenever a density is calculated or entered, the comparison chart shows a note saying your material would float, sink, or stay neutral in water.
What is the density of water?
Pure water has a density of about 1,000 kg/m³ (1 g/cm³), which is the standard reference for liquids. It is one of the 12 materials on the comparison chart and is also available as a one-click example.
Why does my result show as empty?
The calculator needs exactly two inputs to solve for the third. If you fill all three cards, the oldest entry is cleared automatically. It also cannot divide by zero, so entering 0 for volume (when solving density) or 0 for density (when solving volume) will not return a result.
Is my data stored or sent anywhere?
No. Every calculation runs entirely in your browser with JavaScript. Nothing is sent to a server, and no values are saved after you close the page.
No comments yet. Be the first to comment!