Angle Addition & Subtraction
Angle Addition & Subtraction is a mathematics calculator that helps you calculate angle addition & subtraction values from your input data. The formula used is: sum = angle1 + angle2; normalized = ((sum % 360) + 360) % 360. Ensure all inputs share the same unit system (e.g. all metres or all feet) unless the formula converts between units.
Formula
sum = angle1 + angle2; normalized = ((sum % 360) + 360) % 360
Example Calculation
Inputs
- Angle 1: 45 °
- Angle 2: 30 °
With angle 1 = 45° and angle 2 = 30°, the sum is 75° and the difference is 15°. The complement of 45° is 90° − 45° = 45°, and its supplement is 180° − 45° = 135°.
Frequently asked questions
What does this calculator do?
It adds and subtracts two angles and also reports the complement and supplement of the first angle, plus the sum normalised to the 0–360° range.
What are complementary and supplementary angles?
Two angles are complementary if they add to 90° and supplementary if they add to 180°. The calculator shows 90° − angle 1 and 180° − angle 1.
What units should I enter?
Enter both angles in degrees. All results are returned in degrees.
Why normalise the sum to 0–360°?
Angles are periodic, so a sum like 400° represents the same direction as 40°. Normalising keeps the result within a single full turn.
How accurate are the results?
Addition and subtraction are exact; values are rounded only for display.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.