What is the Diamond Painting Drill Count Calculator?
Diamond painting uses tiny resin "drills" placed onto a sticky, color-coded canvas to build a sparkling mosaic image. This calculator estimates how many drills your project needs based on the canvas size and how much of it is actually covered with drills. It's perfect for planning supply orders, comparing kit sizes, or checking whether you have enough beads to finish a piece.
How to use it
Enter your canvas width and height in centimeters, then enter the drill coverage as a percentage. Use 100% for a "full drill" painting that covers the entire canvas, or a lower value (for example 40%) for a "partial drill" design where only part of the image is beaded. The calculator returns the estimated drill count, the total number of grid cells, and a rough number of bags assuming 200 drills per bag.
The formula explained
Standard square and round drills measure about 2.5 mm, or 0.25 cm. Dividing each canvas dimension by 0.25 cm gives the number of drill positions across and down. Multiplying those together gives the total grid cells. Multiplying by the coverage fraction (coverage \(\div\) 100) yields the number of drills you'll actually place:
$$\text{drills} = \frac{W}{0.25} \times \frac{H}{0.25} \times \frac{\text{coverage}}{100}$$
Worked example
For a 30 cm \(\times\) 40 cm full-coverage canvas: drills across = \(30 / 0.25 = 120\), drills down = \(40 / 0.25 = 160\), total cells = \(120 \times 160 = 19{,}200\). At 100% coverage you need 19,200 drills, or about 96 bags of 200.
$$\text{drills} = \frac{30}{0.25} \times \frac{40}{0.25} \times \frac{100}{100} = 19{,}200$$
FAQ
Are these square or round drills? The 0.25 cm size applies to both standard square and round drills, so the count works for either.
Why order extra? Always buy 15–20% more per color than calculated, because drills get lost, damaged, or run short by color.
Does this account for color counts? No—it gives the total drill count across all colors. Your kit's color chart breaks that total down by shade.
