Change The Subject Of A Formula Calculator

Work out change the subject of a formula instantly with clear inputs, formula shown and shareable results.

About Change The Subject Of A Formula Calculator

Changing the subject means rewriting a formula so a different letter stands alone. Using v = u + at as the model, each rearrangement isolates one variable by undoing the operations applied to it.

Formula

The four forms

v = u + at, u = v − at, a = (v − u)/t, t = (v − u)/a

Worked example

With the default values below, Change The Subject Of A Formula Calculator returns Value of the new subject of 26.00000000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Initial value u in v = u + at: 5
Rate a: 3
Time t: 7
Make this the subjectone of v (final value), u (initial value), a (rate), t (time): v (final value)

Results

Value of the new subject: 26.00000000
Formula with the new subject: v = u + at
v = u + at: 26.00000000
Subject chosen: v

Step by step

1Values used
2The four forms
3Value of the new subject= 26.00000000
4Formula with the new subject= v = u + at
5v = u + at= 26.00000000
6Subject chosen= v

Assumptions and limits

The result is derived only from the 4 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 8 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

With u = 5, a = 3, t = 7?

v = 5 + 21 = 26, and rearranging for a gives (26 − 5)/7 = 3 as expected.

Why can't t be the subject when a = 0?

With no acceleration v equals u for every t, so t is not determined — dividing by zero reflects that.