How to Cut a Pie Into 5 Equal Slices (or 3, 7 or 9)

To cut a pie into 5 equal slices, picture a clock on top of it and cut from the center to the 12, then to the 12-minute, 24-minute, 36-minute and 48-minute marks, because each slice needs 72 degrees, which is exactly 12 minutes on a clock face.

Halving works for 2, 4 and 8. For an odd number of people at the table, you need a clock.

Halving is easy. Cut across, turn the pie, cut across again, and you have four slices. Do it once more and you have eight. Most people never cut a pie any other way.

Then five people sit down for dessert. Cutting eight slices and giving three people a second piece is one answer. Cutting five fair slices is a better one, and it takes about a minute once you know the trick.

Why odd numbers are hard

A straight cut across the middle of a round pie always gives two halves. That is why 2, 4 and 8 feel natural: every cut is a full line through the center.

Odd numbers do not work that way. Every slice runs from the center to the crust, and every angle has to be judged by eye. People are bad at that. The fix is to stop judging angles and read positions you already know.

The clock-face trick

Every round pie is a clock. The center is where the hands meet. A full turn is 60 minutes, so splitting the pie into equal slices means splitting 60 minutes evenly.

• 3 slices: 60 / 3 = 20 minutes. Cut to 12, 4 and 8 o'clock. It looks like a peace sign without the bottom stroke, or a Y.
• 5 slices: 60 / 5 = 12 minutes. Cut to the 12, then 12, 24, 36 and 48 minutes past.
• 7 slices: 60 / 7 is about 8.6 minutes. Cut at roughly 0, 8.5, 17, 25.5, 34, 43 and 51.5 minutes.
• 9 slices: 60 / 9 is about 6.7 minutes. Easier route: cut 3 slices first, then split each one into three.

Step by step: 5 slices

• Find the center. Look at the pie from directly above, not from your chair. Mark it with the knife tip.
• Make the first cut to 12 o'clock. This is your anchor. Cut from the center straight out to the crust.
• Score, do not cut. Lightly mark the crust at 12, 24, 36 and 48 minutes with the knife tip. Do not cut yet.
• Check the gaps. Look at the five marks around the edge. If one gap looks bigger, nudge the marks next to it. Fixing a score line costs nothing. Fixing a cut costs a slice.
• Cut from the center to each mark. Wipe the knife between cuts so the filling does not drag.

The table

Here are the numbers for a standard 9-inch pie. The crust length is measured around the outer edge, so you can check your marks with a tape measure or a piece of string if you want to be exact. The circumference of a 9-inch circle is about 28.3 inches.

For a 10-inch pie, multiply the crust numbers by 1.11. For an 8-inch pie, multiply by 0.89. The angles and clock minutes never change.

The string method for 7

Seven is the hardest number, because 8.6 minutes is not a mark anyone can see. If it has to be exact, use string.

• Wrap a piece of string around the outside of the pie dish and pinch where it meets the start.
• Lay the string flat and measure it. For a 9-inch pie it will be close to 28 inches.
• Divide by 7. For 28 inches, that is 4 inches.
• Mark the crust every 4 inches, then cut from the center to each mark.

This works for any number. It is slower than the clock, so save it for 7, 11 and 13.

Mistakes that make slices uneven

• Cutting from your seat. Viewed at an angle, a round pie looks like an oval, and the slices on the far side look smaller than they are. Stand up and look down.
• Missing the center. If the point where all cuts meet is off by half an inch, slices on one side get noticeably wider at the crust. Mark the center first.
• Cutting before checking. Score all the marks, then cut. Never cut one slice at a time around the pie.

Equal size is not always equal pie

A slice is a wedge, so most of it sits near the crust. A slice that is 10 percent wider at the edge holds about 10 percent more pie. Small misses at the crust matter more than small misses near the center.

That is also the idea behind Halfsies, a free daily game where you cut three hand-drawn objects a day exactly in half by eye. A scale weighs both pieces by area, and you score the lighter half divided by the heavier half, times 100. Pies are forgiving. The scale is not. If you want to practice before Thanksgiving dessert, today's three cuts are here. For more on halves and fair shares, see I Cut, You Choose.

FAQ

How do you cut a pie into 5 equal pieces?

Picture a clock on the pie and cut from the center to the 12, then to the 12, 24, 36 and 48 minute marks. Each slice is 72 degrees. Score all five marks on the crust before cutting so you can adjust them.

How do you cut a pie into 3 equal pieces?

Cut from the center to 12, 4 and 8 o'clock on an imaginary clock face. Each slice is 120 degrees, and the cuts form a Y shape.

How do you cut a pie into 7 equal slices?

Measure around the dish with a string, divide the length by 7, and mark the crust at each interval. For a 9-inch pie that is about every 4 inches. Then cut from the center to each mark.

What angle is each slice when a pie is cut into 5?

72 degrees, because a full circle is 360 degrees and 360 divided by 5 is 72.

Does pie size change how you cut odd numbers of slices?

No. The angles and clock positions stay the same for any round pie. Only the crust length per slice changes with the size of the dish.