THE NUMBERS, EXPLAINED
How to use this calculator.
A 1:6 slope moves sideways by one unit for six units of board depth. The angle is measured from the perpendicular reference, not from the board face.
Start with your inputs
Enter slope rise, slope run, board thickness (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Slope rise | 1 |
| Slope run | 6 |
| Board thickness (mm) | 18 |
A worked example
With the example inputs above, angle from perpendicular (degrees) is 9.462322. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Angle from perpendicular (degrees)
atan((1) ÷ (6)) × 180 ÷ π = 9.462322
Side offset (mm)
(18) × (1) ÷ (6) = 3
| Result | Example answer |
|---|---|
| Angle from perpendicular (degrees) | 9.462322 |
| Side offset (mm) | 3 |
How this is calculated
Angle from perpendicular (degrees)
atan(a ÷ b) × 180 ÷ π
Side offset (mm)
c × a ÷ b
Symbols and units
- a
- Slope rise
- b
- Slope run
- c
- Board thickness (mm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
atan returns the inverse tangent in radians. Multiply by 180/π for degrees.
π is the circle constant, approximately 3.141592653589793.
Assumptions and limits
A 1:6 slope moves sideways by one unit for six units of board depth. The angle is measured from the perpendicular reference, not from the board face.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Angle from perpendicular (degrees); Side offset (mm). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: A 1:6 slope moves sideways by one unit for six units of board depth. The angle is measured from the perpendicular reference, not from the board face.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: algebra and proportional reasoning ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →