The grid method copies a small reference onto a larger canvas or wall one square at a time. This calculator works out the size of the squares on both, how many you need, and whether your canvas has the same shape as the reference.
Grid enlargement
How it works
Divide the reference width by the number of squares across to get the square size on the reference. The enlargement factor is canvas width ÷ reference width, and the square size on the canvas is the reference square × that factor.
To keep the image in proportion, the canvas height should be reference height × the same factor.
Worked example
A 20 × 30 cm photo with 5 squares across gives 4 cm squares, in a grid of 5 × 8. On a 60 cm wide canvas the enlargement is × 3, so the canvas squares are 12 cm and the canvas needs to be 90 cm tall to keep the shape.
Good to know
- Draw the grid lightly on the canvas, or use a removable method, so the lines do not show through the paint.
- If the canvas shape does not match, decide first whether to crop the image or leave a border.
Frequently asked questions
What is the grid method in drawing?
It is a way of copying an image by dividing the reference and the canvas into matching grids, then copying one square at a time. It helps keep proportions right when enlarging.
How many grid squares should I use?
More squares give more accuracy but take longer to draw. Detailed areas such as faces often benefit from smaller squares.
Does the grid method work for murals?
Yes. Muralists often use a grid or similar method to scale a small design up to a wall.