Home renovation and materials

Coving length calculator

Uses rectangular-room perimeter and entered exclusions; corner cuts are not optimised.

Your numbers

Use the units shown. Results update as you change valid inputs.

YOUR RESULT

Uses rectangular-room perimeter and entered exclusions; corner cuts are not optimised.

THE NUMBERS, EXPLAINED

How to use this calculator.

Uses rectangular-room perimeter and entered exclusions; corner cuts are not optimised.

Start with your inputs

Enter room length (m), width (m), excluded run (m), stock length (m). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.

InputExample value
Room length (m)5
Width (m)4
Excluded run (m)0
Stock length (m)3

A worked example

With the example inputs above, stock lengths is 6. Change the inputs to explore your own scenario.

Putting the example numbers into the formula

Net coving run (m)
2 × ((5)+(4))-(0) = 18

All results for the example inputs above
ResultExample answer
Stock lengths6
Net coving run (m)18

How this is calculated

Stock lengths

roundUp((2 × (a+b)-c) ÷ d)

Net coving run (m)

2 × (a+b)-c

Symbols and units
a
Room length (m)
b
Width (m)
c
Excluded run (m)
d
Stock length (m)

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

roundUp(x) rounds up to the next whole number. Values within two floating-point rounding units of an integer are treated as that integer.

Assumptions and limits

Uses rectangular-room perimeter and entered exclusions; corner cuts are not optimised.

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?

Stock lengths; Net coving run (m). 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: Uses rectangular-room perimeter and entered exclusions; corner cuts are not optimised.

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.

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 →