Smart Math guide · Advanced Math Ideas

Use Dimensional Analysis for Conversions

Multiply by conversion factors equal to 1 so unwanted units cancel.

All levelsWorked example includedSelf-check included
The method

How to use it

  1. Write the starting quantity with units.
  2. Choose conversion ratios with unwanted units opposite.
  3. Cancel units before multiplying numbers.
Worked example

See it in action

60 mi/h × 5280 ft/mi × 1 h/3600 s = 88 ft/s.

Check your thinking

How to verify it

Miles and hours cancel, leaving ft/s.