Gutter linear-feet calculator

Add your eave runs to get the total linear feet of gutter to buy.

Measure your eave runs and confirm capacity, spacing and coverage against the exact product you buy. Allow extra for corners, waste and slope (~5–10%). Sizes, capacities, spacings and panel lengths vary by product and brand — read the label and the manufacturer’s data.

Calculator

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Result
Total gutter linear feet110.0 ft
Eave runs added3 × (42 + 42 + 26 ft)

Adding your eave runs gives 110.0 linear feet of gutter. Measure each eave (the horizontal edge where the roof meets the wall) and add them — gutters go on the eaves, not the gable rakes. Allow a little extra for corners and waste.

Gutter is sold and priced by the linear foot. So the first number you need is simple: the total length of the eaves that will carry gutter. Measure each eave, add them, and you have it. This calculator sums up to six runs so an L-shape, a U-shape or a house with a porch all fit.

Gutters go on the eaves — the horizontal edges where the roof meets the wall. They do not go on the gable rakes, the sloped edges that climb to the peak. Skip the rakes or you will over-buy.

Formula

linear_feet = run1 + run2 + … + runn

Add every eave run in feet. That is the whole formula. Then add a little for waste — corners, offcuts and the slope drop eat a few feet on a real job (allow ~5–10%).

Worked example

A rectangular house with gutter on the two long eaves and one short eave:

  • Run 1 (front eave): 42 ft
  • Run 2 (back eave): 42 ft
  • Run 3 (one side): 26 ft

42 + 42 + 26 = 110 linear feet. Order 110 ft plus a little extra for corners and waste — round up to full sections when you buy sectional stock.

Measure it right

  • Eaves, not rakes. Only the horizontal edges get gutter. A simple gable roof has two eaves; a hip roof can have four.
  • Measure at the fascia. Run the tape along the fascia board, wall to wall, for each eave.
  • Corners add length. An inside or outside corner turns two runs into one continuous gutter — count both runs, then buy corner pieces separately.
  • Round up. Sectional gutter comes in 10-ft stock; seamless is cut to the run. Either way, buy a bit long.

Once you have the linear feet, feed it into the sections & materials calculator for stock, hangers and end caps, or the cost per linear foot tool to price it.

Frequently asked questions

Do gutters go on every edge of the roof?
No. Gutters go on the eaves — the horizontal roof edges. The sloped gable rakes that run up to the peak stay bare. Measuring the rakes is the most common way people over-order.
How many feet of gutter for a 40 × 30 house?
If it has gutter on both 40-ft eaves and both 30-ft eaves, that is 40 + 40 + 30 + 30 = 140 ft. Many houses only gutter the two long eaves, which would be 80 ft. Measure your actual runs.
Should I add extra for waste?
Yes — allow about 5–10% for corners, offcuts and the slope drop. Buying a couple of feet long is cheaper than a second trip.
Does the slope change the length?
Not meaningfully. Gutter drops about ¼–½ inch per 10 feet, so the diagonal length is essentially the same as the horizontal run. Measure the horizontal eave.