Chess clock

How much time does each player have?

Two chess clocks with increment or delay, a move counter and a flag at zero.

Ready

Black · Moves: 0

10:00

Time control: 10 min 0 s

White · Moves: 0

10:00

Keys: Space passes the move to the other side, P pauses, R resets. White's clock starts with Start or Space.

Time control

Preset

Time per player

minutes

Seconds per move

seconds

Seconds work as

How to use

Pick a time control or set the minutes and seconds per move. Choose whether the seconds are an increment or a delay.
Lay the phone between the players. Select Start (or press Space) to start White's clock.
After each move the player selects their own side. The clock passes to the opponent and the move is counted.
If a clock reaches zero the flag falls and the game stops. Pause stops both clocks, Reset starts over.

Time budgets for 40 moves per player

Time control	min
3+2	4.33
10+0	10
15+10	21.67
90+30	110

Base minutes plus increment seconds; includes the increment added after move 40.

How it works

A chess clock gives each player the same total thinking time. Only the clock of the player to move runs; when they make their move and press their button, their clock stops and the opponent's starts. A player whose time runs out loses on time, which is called the flag falling.

Most games add a little time per move. With an increment (Fischer), the seconds are added to your clock after each move, so you can never lose time by moving fast. With a delay, the clock waits for the seconds at the start of each turn and only then counts down; unused delay is lost. A control is written base plus seconds: 3+2 is 3 minutes with 2 seconds per move. For example, with 90+30 and 40 moves, a player can use up to 90 × 60 + 40 × 30 = 6,600 seconds, or 110 minutes.

This clock does not know the rules of a tournament, such as extra time after move 40, and it does not check the moves. It keeps counting after a reload, but it is a convenient clock for casual play, not an arbiter.

Frequently asked questions

What is the difference between increment and delay?

An increment adds time to your clock after every move, so a quick move can even gain time. A delay just postpones the countdown at the start of your turn; if you move within the delay, your clock does not change.

Who starts?

White. Select Start or press Space and White's clock runs. After White moves they select their side and Black's clock starts.

What happens at zero?

The clock stops, the flag falls for that player and the other clock stays where it was. Select Reset for a new game.

Does it keep running if I lock the phone?

The time keeps counting and shows the right value when you return, but a sound only plays while the page is visible. Use full screen to keep the display awake.

Does the clock add extra time after move 40?

No. It uses one time control throughout the game. Multi-stage tournament controls are not supported.

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