Art and Craft Supplies
Mural grid scaling.
Put a grid on your reference print and a matching, larger grid on the wall, then copy square by square. Enter the sizes and the wall square you want to work with.
Print square = wall square / scale. An 8 x 10 in print scaled to an 8 x 10 ft wall is a 12x enlargement, so 1 ft wall squares match 1 in squares on the print: 8 across and 10 down.
Print, wall and square
Grid
Fill the form and press Calculate.
Worked example
An 8 x 10 in print for a wall painted 8 ft x 10 ft. The wall is 96 x 120 in and the print is 8 x 10 in, so the scale is 12 on both axes. A 1 ft (12 in) wall square matches a 12 / 12 = 1 in square on the print: 8 across and 10 down, 80 squares. A letter-size 11 x 8.5 in print on a 10 x 8 ft wall: the width limits the scale (120 / 11 = 10.91, against 96 / 8.5 = 11.29 for the height), so the image is 10.00 ft wide and 7.73 ft tall, and 1 ft wall squares are 1.100 in on the print, giving 10 columns by 8 rows.
How it works
The enlargement is the largest scale at which the whole picture still fits on the wall, in both directions. The picture is scaled by that amount and covered with square cells of the wall size you choose, counting any partly filled cells at the right and bottom edges. A cell on the print is the wall cell divided by the scale, so one grid on the print maps square for square onto the wall grid.
If the print and wall have different shapes the picture stops at one side and some wall is left over, so crop the print first if you need to fill the whole wall. Use a chalk line or a laser level to snap straight grid lines.
Sources and basis (opened 2026-10-08): 1 in = 25.4 mm and 1 ft = 12 in (304.8 mm) from Inch (Wikipedia). The grid method itself is arithmetic.
FAQ
How do I enlarge a drawing to a wall using a grid?
Draw a grid on the reference, draw a larger grid on the wall with the same number of squares, then copy what is in each small square into its matching big square.
What size should the grid squares be?
Smaller squares are easier to copy accurately and take longer to set out. Pick a size that gives a manageable number of squares, and use smaller squares for detailed areas.
How many squares will I need?
For the example: 8 across x 10 down = 80 squares of 1 ft on an 8 x 10 ft wall.
What if my print and wall are different shapes?
The picture is scaled to fit the smaller direction. In the letter-print example, a 10.00 x 7.73 ft image sits on a 10 x 8 ft wall and the rest of the height is spare.
Can I use a projector instead?
Yes. The grid method needs only a pencil and a measuring tape, and it works well when a projector is not available.
Disclaimer
Results are arithmetic from the numbers you enter. Walls are rarely perfectly square. Measure the actual wall and snap your first lines level before drawing.