You need one uncut sheet of printer paper, short edge at the top. No scissors, tape or clips. Measurements are rounded to the nearest ⅛ inch, as in the app.
moves fold line where it lands Diagrams are drawn on Letter and zoom in after the fold in half; the bar in each corner is 1 inch. Tap a diagram to watch the fold.
Fold it step by step
- 01
Crease down the middle
Fold the sheet in half the long way, press, and open it.
Press one sharp, straight crease.
- 02
Fold the top corners in
Bring the top-right corner down so the top edge lies on the center crease.
Line up the edge, then press.
- 03
And the left corner
Same thing on the left.
A pointy roof.
- 04
Fold the point down
Fold the whole triangle down along its bottom edge.
The fold runs straight across where the flaps end.
- 05
Fold the top down again
Fold the flat top edge down 1⅛ in (2.8 cm). Now the nose is square and thick.Fold the flat top edge down 3.0 cm (1⅛ in). Now the nose is square and thick.
This is the hammer head.
- 06
Fold the top corners in
Fold the top-right corner down so the top edge lies along the center crease.
This stacks extra layers at the front.
- 07
And the left corner
Same on the left: a pointed nose.
The two edges meet on the crease.
- 08
Fold it in half
Fold in half along the crease with the flaps inside.
Squeeze the nose flat.
- 09
Fold down the first wing
Fold the top layer down on a slant: ¾ in (2.0 cm) from the center fold at the nose, ½ in (1.3 cm) from it at the tail.Fold the top layer down on a slant: 2.0 cm (¾ in) from the center fold at the nose, 1.3 cm (½ in) from it at the tail.
The crease slants: farther from the center fold at the nose than at the tail. Measure both ends.
- 10
Turn it over
Flip the plane over.
Nose pointing away.
- 11
Fold down the second wing
Fold this wing down on the same slant as the first one.
Hold them together to check.
- 12
Open the wings
Open the wings flat with a slight upward Y.
Check the shape
Square does not mean indestructible: check the nose after a landing and flatten an opened layer before comparing the next flight.
Before you open the wings, hold the plane closed against a window: both wing outlines should cover each other. Fix an unequal wing crease before reaching for trim.
First flights
Launch: Hold it near the middle of the body and throw with a smooth, firm push.
If it misbehaves
- Dives straight down
- Release level, then bend both back edges up a hair.
- Climbs, then drops
- Flatten those bends a little; throw nearer level.
- Always turns one way
- Compare the wings first. Then bend the edge on the inside of the turn down, or the outside edge up, very slightly.
The app can fly this plane in a simulator. Its distances and paths are simulation output; this page makes no claim about how far a hand-folded Hammer will fly.
More square noses
Two downward folds flatten the front into a blunt edge before a second set of corner folds. A good family for comparing wing variations on the same nose.
Spotted a step that doesn't match your paper? Tell us and we'll check it against the app. How these guides are made.