Diamond Painting Drill Count Calculator
Estimate how many drills (round or square) a diamond painting canvas uses from its size and drill dimension, plus bags to buy.
How it works
Grid = floor(width mm ÷ drill) × floor(height mm ÷ drill) · Drills = grid × coverage · Buy = drills × (1 + spare) · Bags = ceil(buy ÷ per bag)
A diamond painting is a grid of tiny resin drills placed one per cell on an adhesive canvas, so the drill count is the canvas area divided into cells of the drill's size. Round drills are about 2.5 mm and square drills about 2.6 mm, giving slightly different grid densities for the same canvas. Full-drill designs cover the whole canvas (100%), while partial-drill kits leave a printed background, so coverage scales the count. Kits ship with spare drills for spills and losses; a spare margin and a per-bag figure tell you how many replacement bags to order in a colour.
Worked example
A 40 × 50 cm canvas with 2.5 mm round drills is floor(400 ÷ 2.5) × floor(500 ÷ 2.5) = 160 × 200 = 32,000 cells. At 100% coverage with a 15% spare margin that is ceil(32,000 × 1.15) = 36,800 drills — 184 bags of 200.
Frequently asked questions
How many drills are in a typical kit?
It scales with size: a small 20 × 20 cm full-drill piece is around 6,000–7,000 drills, while a 40 × 50 cm one runs 30,000+. Larger and full-drill canvases have dramatically more than small partial-drill designs.
Round vs square — does the count change?
Slightly. Square drills sit edge to edge with no gaps and are a hair larger (~2.6 mm), so a canvas fits marginally fewer of them than round drills (~2.5 mm), which have tiny gaps between them.
Why order spare drills?
Drills get lost, spill, or a colour runs short near the end. Kits include extras for this reason; ordering a 10–20% margin per colour saves you hunting for a matching DMC-coded replacement later.
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This calculator is for educational purposes. Double-check important results before acting on them.