Unitary Method Calculator

Work out unitary method instantly with clear inputs, formula shown and shareable results.

About Unitary Method Calculator

The unitary method reduces to one unit first: divide the known value by the known quantity, then multiply by the new quantity. It is the most reliable way to handle any direct-proportion word problem.

Formula

Unitary method

value per unit = value₁ / quantity₁, then new value = value per unit × quantity₂

Worked example

With the default values below, Unitary Method Calculator returns Value of the new quantity of 150.000000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Known quantityminimum 0: 5
Its total value: 62.5
New quantityminimum 0: 12

Results

Value of the new quantity: 150.000000
Value of one unit: 12.500000
Quantity per unit of value: 0.080000
Change from the known value: 87.500000

Step by step

1Values used
2Unitary method
3Value of the new quantity= 150.000000
4Value of one unit= 12.500000
5Quantity per unit of value= 0.080000
6Change from the known value= 87.500000

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 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

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

Frequently Asked Questions

If 5 items cost 62.50, what do 12 cost?

One item costs 12.50, so 12 items cost 150.

Does it work for inverse relationships?

No. For inverse proportion multiply rather than divide, since the product of the two quantities is what stays constant.