Room area calculator
Calculate a rectangular room area, an explicit waste allowance and complete packages from the coverage printed on the product.
How to use this calculator
How to measure
Measure the finished inside length and width at floor level. For an irregular room, divide it into rectangles and calculate them separately; formula v1 accepts one rectangle.
Worked example
A 4 m × 5 m room is 20 m². With 10% waste the plan is 22 m². Packs covering 2.5 m² require 9 complete packs, or 22.5 m² purchased.
Formula and purchasing method
net area = length × width; planned area = net area × (1 + waste/100); packages = ceil(planned area ÷ coverage per package).
Assumptions
- The measured zone is rectangular.
- Package coverage is copied from the selected product label.
Limitations
- Formula v1 does not merge overlapping room zones.
- Cuts, pattern direction and unusable remnants are represented only by the waste input.
FAQ
Can I enter a non-rectangular room?
Split it into rectangles and add the planned areas outside formula v1.
Why are packages rounded up?
Retail packages are indivisible, so any fraction requires the next complete package.
Sources
Product-specific values must be copied from the exact current label or technical datasheet; linked examples document the method and its limits.
Calculation privacy
Calculations run locally. Form inputs and results stay in your browser.
How storage works and how to delete data