Paver Pattern Cut Waste Calculator

Nobody wastes pavers in the middle of a patio. Every wasted paver is a cut on the perimeter, and perimeter grows with the square root of area while the paver count grows with area. That is the whole reason a small herringbone patio needs a bigger percentage than a large one.

Used only when the input above is set to area and perimeter
Only the edges where pavers actually get cut. An edge that lands on a full course, or that runs into an existing wall you are scribing to anyway, still counts. A straight sawn edge against a slab counts.
Nominal size, joint included, which is how pavers are sold
Running bond 30-40, basketweave 35-45, 90 degree herringbone 55-65, 45 degree herringbone 90-100, curves and circles 100. In a running bond the offcut often starts the next course; a diagonal offcut almost never fits anything.
Breakage in transit, chipped corners you reject, and a few spares kept back for repairs. Cut waste is calculated separately below; this is everything else.
Optional, your own price
Paver Cut Waste Calculator — Pattern, Cuts and OverageBuildFigure

Waste is a perimeter number wearing an area costume

Every guide to paver patios prints a table of pattern waste percentages: five percent for running bond, ten or twelve for herringbone, fifteen for curves. Those figures are averages taken across jobs of a particular size, and they get copied onto jobs of a very different size where they are wrong in a predictable direction.

The reason is simple once you see it. Pavers are only wasted where they are cut, and they are only cut at the edges. The number of cuts scales with the perimeter. The number of pavers scales with the area. Double the linear dimensions of a patio and the perimeter doubles while the paver count quadruples, so the waste percentage halves. A 10 by 10 patio and a 40 by 25 patio laid in the same 45 degree herringbone do not need the same allowance, and the small one needs roughly three times as much of one.

This page works the number the way the job works it: count the cuts along the cut perimeter, decide how much of each cut piece is unusable, and let the percentage fall out. If your patio happens to be around 400 square feet the answer will land near the familiar rule of thumb, which is reassuring rather than coincidental. That is the size most of those rules were written from.

Why the pattern changes the cut count and not just the offcut

Two things vary between patterns and both matter.

The first is how many paver units meet a linear foot of edge. In a running bond laid parallel to the edge, whole pavers run along the edge and only the ends of courses need cutting, so the count is low. In a herringbone every unit approaches the edge at an angle, so more of them touch it. At 45 degrees the diagonal presentation puts roughly forty percent more units against the same foot of edge than the 90 degree version does.

The second is what happens to the piece you cut off. A running bond offcut is a rectangle with two square ends, and it usually starts the next course at the opposite edge, so you lose maybe a third of it. A 45 degree herringbone offcut is a triangle at a fixed angle that would only fit in a mirror-image position that the pattern does not produce in equal numbers. In practice it goes in the skip, which is why the loss field defaults to 95 percent for that pattern.

PatternCut units per foot of edgeTypical loss per cut piece
Running bond or stack bondLow30-40%
BasketweaveLow35-45%
Herringbone, 90 degreesModerate55-65%
Herringbone, 45 degreesHigh90-100%
Curved edge, circle kit, random ashlarHighest100%

Both columns are inputs here rather than fixed constants, because the second one in particular depends on how patient you are with a wet saw and whether you are willing to hunt through a pile of triangles for the one that fits.

A border course is a waste strategy, not a decoration

A soldier or sailor course laid around the perimeter changes what gets cut. The border is laid whole against the edge restraint, and the field pattern dies into the inside face of the border instead of into the open air. The cuts still happen, but they happen against a straight line you control rather than against whatever the excavation ended up as, and on curves the border absorbs the curve so the field can stay square.

The border pavers themselves are counted separately here because they are laid on their long face and consume a different number per foot than the field does. If the border follows a curve it will need its own cuts and its own allowance, which this page does not add for you.

What the number cannot see

Cut waste is a supply question. It says nothing about whether the patio will still be flat in five years, and that is decided underneath, in the base. Base depth depends on the soil you are building on, how well the ground drains, and what will drive or stand on the surface. A patio that carries only foot traffic wants far less base than one a vehicle will cross, and the difference is not a small adjustment. Compaction in thin lifts matters as much as total depth. A base that fails is a rebuild, not a repair, because there is no way to fix it without lifting everything above it.

For the quantities that go under the pavers, use the paver patio calculator, which handles base gravel, bedding sand and initial joint sand for the same area. The perimeter details are on the edge restraint calculator, and the fall across the surface is on the hardscape slope calculator. If any part of the excavation goes deeper than a shovel scrape, have the buried utilities located first through the free national locate service that operates in every state before anything breaks ground.

Questions people ask

Why does this give a lower percentage than the ten percent everyone quotes for herringbone?

Because the ten percent figure is a single number covering two separate things: pavers destroyed by cutting, and pavers lost to breakage, chipping, rejects and spares held back for future repairs. This page splits them. The cut figure is calculated from your actual perimeter and the extra allowance is a separate input defaulting to three percent. Add them and a mid-sized 45 degree herringbone patio lands close to the familiar figure. On a small patio the total will be higher and on a large one lower, which is the point of separating them.

What exactly counts as cut perimeter?

Any edge where the field pattern has to be trimmed to fit. That includes the open edges against lawn or gravel, edges against a house wall or an existing slab, and both sides of anything you lay around such as a post, a tree well or a fire pit. It does not include an edge where the field genuinely lands on a whole module, which happens when you have set out the patio dimensions from the paver size deliberately. If a border course takes all the cutting on one side, that side is still cut perimeter, because the cuts are still made.

Does a larger paver waste more or less than a small one?

Fewer cuts, but each cut costs more. A 12 by 24 slab produces one cut per two feet of edge where a 4 by 8 produces several, so the cut count drops sharply. Against that, each wasted 12 by 24 is worth six 4 by 8s. The two effects partly cancel and the percentage often ends up in the same neighbourhood, but the pieces you throw away are more expensive and a mis-cut on a large format unit is much more painful. Run both sizes through the calculator with your own prices in the cost field to see which way it falls for your job.

Can I just order ten percent extra and be done?

On a job of around 400 square feet in a common pattern, probably. On a 90 square foot landing in a 45 degree herringbone with a curved front edge, ten percent will not cover it, and running short means either a second pallet from a different batch or a visible patch of the wrong colour. Order light and you cannot fix it later; order a few dozen too many and you have spares for the repair you will eventually make when a corner settles or something heavy is dropped. Keep the leftovers dry and out of the sun.

Should I include the border course in the total I take to the yard?

Yes, but keep it as a separate line on the order. Border pavers are frequently a different colour, a different size, or both, and the yard needs them counted separately anyway. The number shown here assumes the border is laid whole on its long face around the cut perimeter. If your border wraps a curve, or you are mitring corners rather than butting them, add for that yourself.

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