TryLights · Measure from the ground

Roofline measurement worksheet

Record only the edges you want lit. Confirm uncertain dimensions before buying. This is a coverage estimate, not an installation specification.

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1. Mark the route

Eave and gable measurementsTwo horizontal eaves flank a symmetrical gable. Measure the full width of the gable once; multiplying by its pitch factor gives both sloping edges together. Eave AEave BFull gable widthRakeRake

Project / date:     Pitch source:  

Lit sectionMeasurement (ft)Calculated lit length (ft)
Horizontal eaves, total
Gable 1: width × factor
Gable 2: width × factor
Porch / other lit edges
Total before allowance
Total × 1.05, round up

Both rakes of one symmetrical gable = full width × √(1 + (rise ÷ 12)²). Factors: 4/12 = 1.054; 6/12 = 1.118; 8/12 = 1.202; 12/12 = 1.414. Calculate different gables separately. Add another sheet for more sections.

2. Record gaps and installation constraints

Unlit gaps / approved cable needed
Power supply / controller location
Wall offset / mounting surface
Exact kit / segment and run limits

The 5% allowance matches the calculator. It does not replace measuring cable gaps or checking approved extensions. Confirm cutting rules, component exposure limits and safe access using the exact kit’s manual.

3. Check the result

Example: (70 ft eaves + 30 ft gable × 1.118 + 12 ft porch) × 1.05 = 121.3 ft → plan for 122 ft. A 100 ft kit is too short for this example.

Use your measurements at trylights.com/calculator. Source and instructions: trylights.com/guides/measuring-a-roofline · Revised 7 September 2026.