Roof Batten Calculator
Estimate batten rows and stock lengths for one roof slope. For two equal slopes, double the one-slope total.
A QUICK WALKTHROUGH
How to use this tool
- Enter the roof width and slope length in metres.
- Enter the batten gauge or spacing in millimetres from the covering manufacturer’s instructions.
- Enter the stock batten length in metres and calculate the estimate.
Formula and scope
Rows = ceil(slope length ÷ (gauge ÷ 1000)). Battens per row = ceil(roof width ÷ stock batten length). One-slope total = rows × battens per row. For two equal slopes, double the total. Offcuts are not reused between rows.
Gauge and limitations
Use the batten gauge specified in the roof-covering manufacturer’s instructions. This quantity estimate is not structural approval. It does not include extra battens at eaves, ridge, hips, valleys, penetrations, or other details.
Assumptions
The roof width and eaves-to-ridge slope length describe one slope, and stock lengths are used independently for every row. Measure and plan for actual roof geometry and project requirements.
Local processing
The estimate is calculated in your browser from the values you enter.
GOOD TO KNOW
Common questions
How do I estimate two roof slopes?
For two equal slopes, double the one-slope total. Calculate separately if the slopes differ.
Where should the gauge come from?
Use the roof-covering manufacturer’s instructions. The calculator does not determine a safe or structurally approved spacing.
Does it account for offcuts or extra detailing?
No. Offcuts are not reused across rows, and extra requirements at eaves, ridge, or penetrations are not modeled.