Quick answer
The windmill bingo pattern is a pinwheel: four blades run diagonally from the free space out to the corners, and each blade has a flag that turns the same way, so the shape looks like it's spinning. It covers 13 squares and needs 12 numbers. One card has a 5.4% chance by call 60, and with 500 cards in play the first windmill typically appears around call 47.
Which squares make the windmill?
Start with a letter X, then add a flag to each blade, all turning the same direction:
- Hub: the free space
- Blades (the X): B1, I2, G2, O1, I4, G4, B5, O5
- Flags: I1 (top left blade), O2 (top right), G5 (bottom right), B4 (bottom left)
13 squares, 12 numbers. Because each flag is a quarter turn from the last, the shape has a spinning look, like a pinwheel or the sails of a windmill.
Windmill layouts vary between halls more than most shapes. Some draw four solid blocks in the corners joined through the middle. If your hall’s version differs, the odds below won’t apply exactly, but our bingo odds calculator can help.
Windmill odds by call
Exact single-card figures:
| Calls made | Chance one card has the windmill |
|---|---|
| 40 | 0.02% |
| 50 | 0.46% |
| 60 | 5.4% |
| 70 | 41% |
Half of single cards finish by call 72. In a room, our simulation puts the first windmill at about call 55 with 50 cards and call 47 with 500 cards. Turning it a quarter turn gives the same shape, so there’s no separate crazy version (though a mirror-image windmill spinning the other way is a different set of squares).
Tips for players
- Build from the X. Eight of your 12 numbers are the letter X squares.
- Flags are all on the edges. I1, O2, G5 and B4 each sit next to a corner.
- N calls don’t help. The only N square is the free space hub.
Tips for callers and hosts
The windmill fits farm-themed nights, county-fair bingo, Dutch heritage events and spring festivals. At 12 numbers it’s a medium-to-long game, good for the middle-to-late part of a session.
A neat sequence: play the letter X earlier, then announce the windmill as “the X with four flags.” Players who know the X will catch on quickly.
Variations
- Mirror windmill: flags turning the other way (G1, O4, I5, B2).
- Corner-block windmill: four 2x2 stamps in the corners joined by the free space, 17 squares and 16 numbers.
- Letter X: just the blades. See the letter X.
Frequently asked questions
What squares make a windmill in bingo?
In the pinwheel version shown here: both diagonals (the four corners and I2, G2, I4, G4) plus the free space, and one extra square beside each corner, I1, O2, G5 and B4, which gives the blades their spin.
How many numbers do you need for the windmill?
Twelve. The windmill covers 13 squares, and the free space is the hub.
Is the windmill the same in every bingo hall?
No. Some halls draw a windmill as four corner blocks joined by the center, so check your hall's pattern board before you play.
Keep reading
Letter X Bingo Pattern: Rules, Odds & Tips
The letter X bingo pattern is both diagonals crossing at the free space: 9 squares and 8 numbers. See the layout, the exact odds by call, and tips.
Sputnik Bingo Pattern: Rules, Odds & Tips
The sputnik bingo pattern is the small frame around the free space plus the four corners, like a satellite with antennas: 12 numbers. See the odds by call.
Postage Stamp Bingo Pattern: Rules, Odds & Tips
Postage stamp bingo is a 2x2 block of four squares in any corner of the card. See all four positions, the exact odds by call, and tips for hosts.
Bingo Patterns
Every bingo pattern with a picture, rules and how many numbers you need.