A diamond painting calculator tells you exactly how many resin drills (also called beads or diamonds) you need for a custom canvas. Because drill counts depend on canvas dimensions, drill size, and type (round or square), calculating manually is tedious and error-prone. Enter your project details below to instantly get total drill counts, per-color estimates, and an estimated completion time.
Canvas Details
Enter your canvas size and drill specifications
Used to estimate average drills per color
Canvas Coverage
—%Round drills leave small gaps (~78% coverage); square drills cover ~96%
Common Canvas Size Reference
Total drills for standard 2.5mm round drills
| Canvas Size (cm) | Canvas Size (in) | Total Drills | Est. Hours |
|---|---|---|---|
| 20 × 20 cm | 8 × 8 in | 6,400 | ~21 hrs |
| 30 × 30 cm | 12 × 12 in | 14,400 | ~48 hrs |
| 30 × 40 cm | 12 × 16 in | 19,200 | ~64 hrs |
| 40 × 50 cm | 16 × 20 in | 32,000 | ~107 hrs |
| 50 × 70 cm | 20 × 28 in | 56,000 | ~187 hrs |
| 60 × 80 cm | 24 × 32 in | 76,800 | ~256 hrs |
How to Use the Diamond Painting Calculator
Diamond painting has become one of the fastest-growing crafts worldwide, combining the meditative focus of cross-stitch with the sparkle of rhinestone art. Before starting any project — especially a custom canvas — knowing exactly how many resin drills you need prevents both shortages and wasteful over-ordering. This diamond painting calculator gives you drill counts, per-color estimates, and an estimated time to completion in seconds.
Step 1: Choose your unit and enter canvas size
Toggle between centimetres (cm) and inches (in) at the top of the calculator, then enter your canvas width and height. Most diamond painting canvases are sold in centimetres — common sizes include 30 × 40 cm, 40 × 50 cm, and 60 × 80 cm. If you are working from a kit that lists inches, switch to the imperial toggle first.
Step 2: Select drill type and size
Choose round drills or square drills. Round drills are the most common choice for beginners — they are easier to pick up and place, and small gaps between drills are expected. Square drills fit edge-to-edge like tiles and produce a more polished mosaic finish, but require precise alignment. Most canvases use 2.5mm drills (the standard size). Select 2.8mm or 3.0mm if your canvas grid specifies a larger drill pitch.
Step 3: Enter your color count
Enter the number of distinct colors in your design. This number is used to calculate the average drills per color. Keep in mind that in a realistic design, background colors typically use far more drills than accent or detail colors. The calculator distributes drills evenly across colors as a baseline estimate — always add a 10–15% buffer when ordering individual color bags.
Step 4: Read your results
After clicking Calculate, the tool shows total drills needed, average drills per color, canvas area, and estimated hours to complete. The canvas coverage bar shows the percentage of the canvas physically covered by drills — round drills achieve approximately 78% coverage due to circular gaps, while square drills achieve approximately 96%. The quick size reference table below the calculator lets you compare your canvas against common standard sizes at a glance.
Planning tips for large canvases
For large projects over 40 × 50 cm, plan to work in sections and set aside dedicated time blocks. Most crafters complete 200–400 drills per hour; the calculator uses 300 drills per hour as a moderate estimate. A 60 × 80 cm canvas with ~77,000 drills represents roughly 250 hours of work — spread over several months at 2–3 hours per session. Sort your drill bags by color number before starting to dramatically reduce time spent searching for the right color mid-session.
FAQ
Is this diamond painting calculator free?
Yes, the diamond painting calculator is completely free with no limits. You can calculate drills for as many canvas sizes and projects as you need. No account required — all calculations happen instantly in your browser.
Is my data private and safe?
Yes. Everything runs locally in your browser using client-side JavaScript. No information you enter is ever sent to a server. Your canvas dimensions and project details stay entirely on your device.
How many drills does a diamond painting use per square centimeter?
For the standard 2.5mm drill (the most common size), each square centimeter of canvas holds approximately 16 drills (4 × 4 grid). A 30 × 40 cm canvas therefore needs roughly 19,200 drills total. Square drills pack slightly more densely, so the count is approximately the same but with slightly better coverage.
What is the difference between round and square drills?
Round drills are easier to place and more forgiving for beginners — gaps between drills are part of the design. Square drills fit together like tiles with no gaps, producing a mosaic-like finish with better canvas coverage and a slightly more polished look. Square drills require more precision during placement but produce a denser, more complete result.
How many drills per color should I order?
Most diamond painting kits include approximately 20–30% extra drills per color as a safety buffer. If you are ordering custom loose drills, the calculator estimates drills per color by dividing total drills equally — but in practice, background colors may use three to four times more drills than accent colors. Add at least 10–15% overage per color to avoid running short.
How long does a diamond painting take to complete?
Completion time depends heavily on drill size, working pace, and session length. On average, most crafters place 200–400 drills per hour. The calculator estimates time at a moderate pace of 300 drills per hour. A small 20 × 20 cm canvas may take 4–6 hours; a large 60 × 80 cm canvas can take 80–150 hours spread across weeks or months.
What canvas size is good for beginners?
For beginners, a canvas of 20 × 30 cm to 30 × 40 cm is ideal. This size is small enough to complete in a reasonable time (8–15 hours) but large enough to see detail in the finished piece. Avoid canvases larger than 40 × 50 cm for your first project, as the sheer number of drills can be overwhelming.
Do I need to buy extra drills as a buffer?
Yes — always purchase 10–15% more drills than calculated, especially for custom designs where you are sourcing individual colors. Drills can be lost during placement, and slight miscounts in the design can leave you short on a specific color. Most reputable kit suppliers include extra drills, but custom orders typically do not.