What is Circle Sudoku?
Circle Sudoku (sometimes called Circular Sudoku, Round Sudoku or Target Sudoku) is a friendly twist on the puzzle you know. Instead of squares in rows and columns, the board is shaped like a bullseye — six rings inside one another, sliced into six pie-slice sectors. Every little curved piece is one cell.
If you’ve already tried our 6×6 sudoku you’ve seen the same numbers (1 to 6). Circle Sudoku uses those digits too, just arranged in a round grid. That makes it a perfect next puzzle for kids who can already solve a 6×6 grid and want something new to look at.
The whole board has 36 cells — six rings times six sectors. Some of them start with numbers already in them (the "givens"), and your job is to work out the rest using three simple rules.
The 3 simple rules
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Every ring uses 1–6
A ring is one full circle going around the board. There are six of them, from a tiny inner ring to a big outer ring. Each ring must contain the numbers 1 to 6 — no repeats.
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Every sector uses 1–6
A sector is one pie slice going from the centre to the edge. There are six sectors. Each one must also contain the numbers 1 to 6 — no repeats.
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Every arc box uses 1–6
The board is split into six curved arc boxes of three rings × two sectors. The heavy black lines on the board show where one arc box ends and the next begins. Each arc box needs 1 to 6 once each.
How to read the circular board
Learning to "see" the three groups takes a minute at first, but gets quick. A ring is easy — it’s the band at the same distance from the centre. A sector is a slice — like a piece of pizza going from the middle out to the edge. An arc box is where a few rings and a couple of sectors meet, marked out by thicker black lines.
Before you place a number, look at all three groups: the ring your cell is in, the sector it’s in, and the arc box it sits in. The number you pick can’t repeat inside any of those three.
Tip: the innermost ring has only six tiny cells packed tight together. Kids often solve it first because every cell is touched by three short groups. Once the inner ring is done, use it as a "compass" while you work outward — a bit like what you might have seen in our Easy 9×9 sudoku.
Easy strategies for kids
- ✨ Solve the inner ring first — only six tight cells
- 🍕 Count the givens in each sector and finish the fullest ones first
- 🎨 Use the coloured arc boxes as a visual map of each group
- ✏️ Tap Notes to write small candidate numbers in a cell
- 🔎 Tap Check to spot any wrong digit before it ruins your day
If you’ve never played any sudoku before, start with 4×4 sudoku or 6×6 sudoku first — the circular layout is easier once rows and columns feel natural. Most kids pick up Circle Sudoku after about five puzzles.
Circle Sudoku vs. square sudoku
- 🔵 Circle Sudoku uses a round grid — rings, sectors and arc boxes
- ⬛ Square sudoku uses a flat grid — rows, columns and boxes
- 🔢 Circle Sudoku uses digits 1–6 (like our 6×6), square sudoku uses 1–9
- ⏱ Fewer cells mean Circle puzzles are quicker — great for short breaks
- 🎨 The round shape looks very different, which keeps things fresh
Why kids love Circle Sudoku
- 🧠 Trains spatial thinking — ring/sector/arc is a new mental map
- 🎨 The coloured arc boxes make it feel like a bright wheel game
- 🕵️ Detective brain — spot the missing digit by scanning three groups
- ⏱️ Quick wins on Easy — most kids finish in under 5 minutes
- 📱 Looks gorgeous on phones and tablets
Ready for more?
Once Easy Circle Sudoku feels comfortable, try Medium Circle Sudoku. From there you can graduate to Hard Circle Sudoku, and finally take on Expert Circle Sudoku — our toughest circular puzzle with only eleven starter numbers.
Want a totally different brain workout? Try our Killer Sudoku (sudoku with cage sums), Jigsaw Sudoku (sudoku with wiggly boxes), or X-Sudoku (classic sudoku with two extra diagonals).
Frequently asked questions
What age is Circle Sudoku good for?
Most kids enjoy Circle Sudoku from about 7 years old, once they’re comfortable counting to six and recognising repeats. The 36-cell board and 1–6 digits make it one of the friendliest sudoku variants for beginners.
Is Circle Sudoku harder than normal sudoku?
Not really! The round grid looks unusual at first, but there are fewer cells (36 vs 81) and fewer digits (1–6 vs 1–9). Most kids find Easy Circle Sudoku quicker than classic Easy sudoku.
Is Circle Sudoku the same as Round Sudoku or Target Sudoku?
Yes — Circle Sudoku, Circular Sudoku, Round Sudoku, Target Sudoku and Radial Sudoku are all names for the same puzzle. Different publishers use different names, but the rules never change.
What are the rules of Circle Sudoku?
There are three rules: every ring (band around the board) must contain 1–6 once; every sector (pie slice) must contain 1–6 once; every arc box (three rings × two sectors) must contain 1–6 once. That’s it!
Can I play without making an account?
Yes! Every game on this site is free, with no signup, no email, and no ads in the way of the puzzle.
Does it save my progress?
Yes — your puzzle, notes and timer save automatically in your browser. Close the tab and come back later, it’ll still be there.
Try other sudoku games
Different rules, same friendly board. Pick a sibling puzzle to play next.