Chess Clock
Set a time control — from bullet 1+0 to classical — put the phone or laptop beside the board, and tap your color after each move. Increment, flag-fall, pause, and honest per-player stats at the end.
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Last reviewed: July 20, 2026 · Formulas verified by automated tests before every release.
How do I use an online chess clock for over-the-board play?
Pick a time control (5+0 blitz and 10+0 rapid are the casual favorites), place this screen beside the board, and after each move tap YOUR color's half — that stops your clock and starts your opponent's. The «+2» style increment adds seconds back after every move you make. Run out — your flag falls and the clock declares the winner on time.
Why the increment changed chess
Pure countdown controls (5+0) end many games in a flag-race: whoever moves faster wins, position be damned. The Fischer increment — a few seconds added after every move — keeps endgames honest: you can always afford to make a move, but never to think for free. That's why 3+2 overtook 5+0 as the blitz standard online, and why 15+10 became the rapid norm in official play. If you're new to timed chess, start with an increment; your endgames will thank you.
Clock etiquette worth knowing
Three habits that keep timed games friendly: press with the hand that moved (it's the FIDE rule, and it prevents the two-hands blur); never hover over the clock while your opponent thinks; and when a flag falls, it falls — time is part of the game, not an inconvenience attached to it. For solo training between games, our pomodoro timer handles the study sessions, and the plain 5-minute timer covers everything else that needs a countdown.
Sources, assumptions and limitations
- Assumptions: Timing runs at 10 Hz (tenths of a second) with monotonic-clock correction against tab throttling.Fischer increment is added after a completed move (on your press), per standard digital-clock behavior.First tap starts the game and passes the move to the opponent — the presser is the one who just moved.The clock keeps running in a background tab, but for fairness keep the screen on and visible.No accounts, no recording — games exist only on your screen.
- Sources:
- Last reviewed: by the CalcNotebook team
Frequently asked questions
How does a chess clock work?
Two linked timers, only one running at a time. After making your move you press YOUR side — that stops your clock and starts your opponent's. Run out of time and your flag falls: you lose on time, regardless of the position (with narrow rule exceptions when the opponent lacks mating material). This online clock works the same way: tap your half after you move.
What do time controls like 5+0, 3+2 or 15+10 mean?
Minutes + increment. The first number is each player's starting bank in minutes; the second is seconds added to your clock after every move you make. So 3+2 means 3 minutes each plus 2 seconds per move. With increment, endgames stay playable instead of degenerating into flag-races.
What are bullet, blitz, rapid and classical?
Speed categories: bullet is under ~3 minutes per player (1+0 the classic), blitz roughly 3–10 (3+2 and 5+0 dominate), rapid roughly 10–60 (10+0, 15+10), classical is longer. Casual over-the-board play most commonly picks 5+0 or 10+0 — both are preset buttons above.
Who presses the clock, and with which hand?
The player who just moved presses their own side — never your opponent's. Over the board, FIDE rules require pressing with the same hand that moved the piece. On this clock the same logic applies: the very first tap is made by whoever moves first... after their move, which starts the opponent's timer.
Why does the display show tenths of a second?
Below one minute, whole seconds are too coarse — bullet and blitz scrambles are decided in tenths. The clock switches to a 0.1s display exactly when it starts to matter, the same way tournament digital clocks do.
Does this work offline / do you track my games?
Once the page is open, the clock runs entirely in your browser — no connection needed mid-game, nothing recorded, no account. The post-game stats (moves, time used, average per move) exist only on your screen and vanish on reset.