Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
10ft drip edge pieces needed
19
Total linear feet purchased
190
ft
Exact pieces before rounding
18.31
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How to use this
- 1Enter total eave + rake length (ft).
- 2Enter overlap per joint (in).
- 3Read your 10ft drip edge pieces needed on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Drip edge is a metal flashing installed along a roof's eaves and rakes (the horizontal and sloped edges) to direct water away from the fascia and into the gutter rather than letting it wick back under the shingles and rot the roof deck, and it's sold in standard 10-foot lengths. This calculator takes the total linear footage of your roof's perimeter — eaves plus rakes, which you can get by adding up each edge's length — and divides by 10 feet per piece, rounding up since drip edge pieces overlap slightly at joints (usually 1-2 inches) rather than butting perfectly end to end. It also applies a small waste factor for that overlap and for any cuts needed at corners, valleys, or irregular roof shapes. Drip edge is inexpensive relative to the rest of a roofing job but is a code requirement in most jurisdictions and one of the most common items missed or under-ordered by first-time DIY roofers who focus heavily on shingle and underlayment counts while treating the perimeter flashing as an afterthought.
Worked example
Using the values the calculator loads with:
Inputs
- Total eave + rake length: 180 ft
- Overlap per joint: 2 in
Results
- 10ft drip edge pieces needed: 19
- Total linear feet purchased: 190
- Exact pieces before rounding: 18.31
What each field means
Inputs
- Total eave + rake length (ft)
- The total eave + rake length used in the calculation, measured in ft. Starts at 180 ft so you have a working example on load.
- Overlap per joint (in)
- The overlap per joint used in the calculation, measured in in. Starts at 2 in so you have a working example on load. Accepted range: 0–6 in.
Results
- 10ft drip edge pieces needed
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total linear feet purchased
- ft
- Exact pieces before rounding
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Do I need drip edge on both eaves and rakes?
Yes, most codes require drip edge along both the horizontal eaves and the sloped rake edges of a roof, installed under the underlayment at eaves and over the underlayment at rakes, per most manufacturer and code specifications.
What length does drip edge come in?
Standard drip edge is sold in 10-foot lengths, though some suppliers carry 8-foot or custom-bent lengths for larger commercial jobs; residential DIY projects almost always use the 10-foot standard.
How much overlap does drip edge need at joints?
Most installations use a 1-2 inch overlap at each joint to ensure continuous water shedding without gaps, which slightly reduces the effective coverage per piece versus the full 10 feet.
Is drip edge required by code?
In most U.S. jurisdictions under the IRC, yes — drip edge is a code requirement at eaves and rakes on new roofing installations, so it shouldn't be skipped even on a budget reroof.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
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Turn roofing squares into the exact bundle count to order for standard 3-tab or architectural shingles.
Underlayment Rolls Calculator
Calculate rolls of roofing felt or synthetic underlayment needed to cover your roof deck.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Drip Edge Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/drip-edge-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/drip-edge-calculator" target="_blank" rel="noopener">Drip Edge Calculator — RevenueLab</a> (2026).</p>
Source: [Drip Edge Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/drip-edge-calculator) (2026).