Free Density Calculator Online

Density Calculator: Solve for Density, Mass, or Volume From the Other Two

Density ties mass and volume together with one of the shortest formulas in physics: density equals mass divided by volume. This calculator flips that relationship around so you can solve for whichever piece you're missing — give it mass and volume and it returns density, give it density and volume and it returns mass, or give it density and mass and it returns volume. Type any two of the three numbers into the page and the third appears immediately, computed as JavaScript in your browser with nothing to upload and no waiting on a result.

Despite the short formula, density questions come up in a wide range of everyday and technical situations — figuring out whether an object will float, checking whether a metal sample matches a claimed material, converting a recipe between weight and volume, or working out the mass of a liquid that only ships by the gallon or liter. Rather than rearranging the formula by hand each time depending on which value you already know, this tool handles all three directions from a single input screen.

How to Use the Density Calculator

1. Choose which quantity you want to solve for at the top of the tool: Find density, Find mass, or Find volume.
2. The form then shows input fields for the other two quantities. In "Find density" mode, enter Mass (g) and Volume (cm³). In "Find mass" mode, enter Density (g/cm³) and Volume (cm³). In "Find volume" mode, enter Mass (g) and Density (g/cm³).
3. As soon as both required fields have a positive number in them, the result appears below, labeled with the quantity you chose and its unit.
4. A reference table of common material densities sits underneath the calculator, useful for a rough plausibility check against your own result or for filling in a density value when you don't have one handy.

All three inputs and the result on this page work in grams and cubic centimeters — mass in grams, volume in cubic centimeters, density in grams per cubic centimeter. If your numbers are in different units, such as kilograms or liters, convert them to grams and cubic centimeters first (1 liter equals 1,000 cubic centimeters, and 1 kilogram equals 1,000 grams) so the result comes out correctly scaled.

The Density Formula, Solved Three Ways

The underlying relationship is density = mass ÷ volume. Rearranged algebraically, the same equation gives the other two forms this calculator uses: mass = density × volume, and volume = mass ÷ density. Whichever two values you supply, the calculator picks the matching rearrangement and computes the third — there's no separate lookup table involved, just the one formula applied in whichever direction fills the gap.

A density figure in grams per cubic centimeter converts directly to kilograms per cubic meter by multiplying by 1,000, since a cubic meter contains exactly 1,000,000 cubic centimeters and a kilogram contains exactly 1,000 grams — the two unit changes cancel down to a clean factor of 1,000. Water's familiar density of 1 g/cm³, for instance, is the same physical quantity as 1,000 kg/m³; neither number is "more correct" than the other, they're just expressed in different metric units.

Worked Example: 100 Grams in 50 Cubic Centimeters

Take a sample with a mass of 100 grams that occupies 50 cubic centimeters of volume. Dividing mass by volume: 100 ÷ 50 = 2 grams per cubic centimeter. That same density, expressed in kilograms per cubic meter, is 2 × 1,000 = 2,000 kg/m³. Running the calculation the other direction confirms the relationship holds: a density of 2 g/cm³ times a volume of 50 cm³ gives back a mass of 100 grams, and a mass of 100 grams divided by a density of 2 g/cm³ gives back a volume of 50 cm³ — the three quantities are locked together, and knowing any two always pins down the third.

Common Material Densities for Reference

The table below lists the reference densities shown alongside the calculator, useful for spot-checking a computed result or for estimating a density value when you don't have a precise one on hand.

Material	Density (g/cm³)
Air	0.001225
Ice	0.917
Water	1.0
Wood (oak)	0.6
Concrete	2.4
Aluminum	2.7
Iron	7.87
Gold	19.32

Notice how much these values span — air is roughly 16,000 times less dense than gold — which is exactly why density is such a useful identifying property. An object's color or size alone rarely tells you what it's made of, but its density, combined with a bit of context, narrows the possibilities considerably. A sample that weighs in far from any plausible material's density is also a good sign that the mass or volume measurement feeding the calculator needs a second look.

Why People Look Up Density

• Predicting whether something floats. An object with a lower density than the liquid it's placed in floats; one with a higher density sinks. Comparing a material's density against water's 1 g/cm³ is the quickest way to reason about this before ever touching water.
• Checking a metal's identity. A classic way to distinguish gold (19.32 g/cm³) from a much less dense look-alike is to weigh a sample, measure how much water it displaces to get its volume, then divide — a real-world application of exactly the formula this calculator runs.
• Converting a recipe or formulation between weight and volume. Cooking, baking, and chemistry recipes sometimes specify an ingredient by weight and sometimes by volume; if you know the ingredient's density, this calculator converts cleanly between the two.
• Estimating shipping weight from a known volume. Freight and packaging calculations often start from a material's typical density and a package's volume to estimate mass before a shipment is ever weighed.
• Coursework and lab reports. Density is one of the first calculations introduced in a physical science curriculum, and this tool works well as a fast way to check homework or lab measurements against the expected formula.

Density Versus Weight: A Common Mix-Up

Density and weight get confused often enough that it's worth spelling out the difference. Weight depends on how much of a substance you have — a bathtub of water weighs far more than a teaspoon of water — while density is a property of the material itself, independent of how much of it you're holding. A gold ring and a gold bar have the same density, 19.32 g/cm³, even though the bar has vastly more mass and vastly more volume. This is exactly why density is useful for identifying a material: it stays constant regardless of sample size, so a small chip of metal and a large ingot of the same metal should return the same density figure from this calculator, even though their individual mass and volume numbers look nothing alike.

A related point of confusion is mass versus weight themselves. Mass, measured in grams here, is a fixed property of an object. Weight is the force gravity exerts on that mass, and it changes depending on where the object is — an object's mass on the Moon is identical to its mass on Earth, even though its weight there is roughly a sixth of what a scale would show on Earth. This calculator works entirely in mass (grams), not weight, so the results hold regardless of gravitational conditions, which matters if you're ever working with a density figure sourced from a context where "weight" and "mass" were used loosely as synonyms.

How Temperature and Physical State Change Density

The density figures in the reference table above describe a material under fairly ordinary conditions, but density isn't a truly fixed constant for most substances — it shifts with temperature and, for gases especially, with pressure. Heating most materials causes them to expand slightly, spreading the same mass over a bit more volume and nudging density down; cooling has the opposite effect. Water is a well-known partial exception: it's actually slightly denser at around 4°C than right at its freezing point, which is part of why ice, at 0.917 g/cm³, floats on liquid water instead of sinking. Gases are far more sensitive to both temperature and pressure than solids or liquids are, since air (at roughly 0.001225 g/cm³ under typical conditions near sea level) compresses and expands noticeably as pressure and temperature change, unlike a solid metal bar, which barely changes volume at all across an ordinary temperature range. None of this changes how the calculator works — it simply takes whatever mass and volume (or density and one of the other two) you enter — but it's a useful reminder that a "density of X" figure pulled from a reference table implicitly assumes a particular temperature, and comparing a measured result against that reference is most meaningful when conditions roughly match.

A Few Things Worth Double-Checking

Density calculations go wrong most often because of a unit mismatch rather than a formula mistake — entering a mass in kilograms while the volume is in cubic centimeters, for example, produces a result a thousand times off from the correct answer. Always confirm mass is in grams and volume is in cubic centimeters before reading the result, or convert first if your original figures use different units. A volume of zero is also rejected outright, since dividing mass by zero has no defined answer; if you're solving for density or mass and the volume field is empty or zero, the calculator won't return a result until a positive volume is entered.

Can this calculator handle liquids as well as solids?

Yes — the density formula doesn't care whether the substance is solid, liquid, or gas, only that you can express its mass and the volume it occupies in grams and cubic centimeters. Measuring a liquid's volume is usually simpler than a solid's, since it takes the shape of whatever container holds it.

What's the difference between density and specific gravity?

Specific gravity is a material's density divided by the density of a reference substance, almost always water at 1 g/cm³ — which means specific gravity and density in g/cm³ are numerically identical for most everyday comparisons, just expressed as a unitless ratio rather than a density figure. This calculator reports density directly rather than a separate specific-gravity figure.

Why does the calculator require grams and cubic centimeters specifically?

Grams and cubic centimeters keep the arithmetic simple and match how density is most commonly reported for everyday materials, and 1 gram per cubic centimeter conveniently equals 1,000 kilograms per cubic meter, so converting the result to the other common metric density unit is a single multiplication rather than a separate formula.

How precise is the result the calculator shows?

The result is carried to six decimal places internally, though many real-world measurements aren't precise enough to justify trusting the answer past two or three significant figures — the extra decimal places mainly help when you're chaining this result into a further calculation rather than reading it as a final measured value.

Does the material's shape affect the density I calculate?

No. Density only cares about total mass and total volume, not the shape those quantities are arranged into. A material bent into a coil, cast into a block, or shaved into powder has the same density in every case, as long as it's the same solid material without added air gaps — a crumpled sheet of foil that traps air pockets, for instance, would measure a lower "bulk" density than a flat, solid sheet of the identical metal, because the trapped air adds volume without adding mass.

Can I use this calculator for a mixture, like an alloy or a solution?

Yes, as long as you can measure or already know the mixture's overall mass and volume as a single combined sample — the formula doesn't need to know what's inside the mixture, only how much it weighs and how much space it occupies. Keep in mind that a mixture's density is a property of that specific blend and generally won't match either of its individual ingredients' densities on their own.

Related Tools

If your original numbers are in pounds, ounces, or kilograms rather than grams, the weight converter gets them into grams first. For volume figures given in liters, gallons, or cubic inches instead of cubic centimeters, the volume converter handles that conversion before you plug numbers into density. And if a dimension needs converting from inches or feet to centimeters before you can compute a volume at all, the length converter covers that first step.