Redstone Timing: Repeaters and Reach

Verified: Java 26.3 / Bedrock 26.50 · 2026-09-16 · repeater settings and dust reach shared by both editions; pulse handling differs · Updated 2026-09-16

A lamp that lights late, a door that closes behind you, a farm that fires every few seconds: every redstone build that waits for something is spending two budgets, time counted in ticks and distance counted in blocks of dust. This guide gives you the rules the redstone tick calculator runs on, a table of repeater chains for common delays, the arithmetic for how many repeaters a long line needs, and the component timings two sources agree on, along with the ones they do not.

Two clocks, one ratio

The game advances 20 times a second, and each step is a game tick of 0.05 seconds. Redstone builders count in redstone ticks instead, and a redstone tick is two game ticks, a tenth of a second, so ten of them make a second. The editions treat that unit differently. In Java it is a community convention: the game code and the /tick command count game ticks, and a few Java redstone events really do happen one game tick apart, which the Minecraft Wiki writes as half a redstone tick. In Bedrock the redstone tick is how the redstone system is built. Each one is split into a produce phase and a consume phase, and repeaters, comparators, redstone torches and observers read their inputs on the first.

Four settings, and the chain rule

A repeater's delay is set by clicking it: 2, 4, 6 or 8 game ticks, which is 1 to 4 redstone ticks, cycling back to the first setting after the fourth. Delays add along a chain, so a longer wait means more repeaters, and the fewest repeaters for a delay of R redstone ticks is R divided by 4, rounded up. The last repeater takes whatever is left over. The wiki's own illustration is a repeater at 8 game ticks followed by one at 2, which is half a second, and the table below carries that pattern further.

Two things fall out of the table. Every delay a repeater chain can make is a whole number of tenths of a second, because every setting is an even number of game ticks; 0.35 seconds is 7 game ticks, and the nearest a chain can get is 6 or 8. And the two-second row is worth remembering, because crafty.gg's calculator uses the same example and arrives at the same five repeaters.

Fifteen blocks, then a repeater

Dust is the other budget. The block of dust next to a source carries strength 15 and every block after it is one lower, so the fifteenth carries 1 and a sixteenth would carry nothing. A repeater accepts any strength from 1 up and sends 15 onward, but it sits in the line and uses a block of its own. Put those together and a line with r repeaters can span 16r + 15 blocks. Turned around, a line of L blocks needs L minus 15, divided by 16 and rounded up, and never fewer than zero.

The last column is the part people miss. Every repeater costs at least one redstone tick, so distance sets a floor on speed: a signal cannot cross 100 blocks of flat dust and repeaters in under 0.6 seconds, whatever the settings. The formula is checked in this site's test suite against a block-by-block simulation of the signal and against a search over every placement of dust and repeaters on lines up to 600 blocks long, and all three agree on every length.

Planning a delay line

The two budgets meet when a signal has to travel and also arrive late. Take a lamp 40 blocks from its lever that should light a second and a half after the pull. The distance needs 2 repeaters and the delay needs 4, so the line gets 4, the larger of the two, and the chain rule sets them to 4, 4, 4 and 3. The planner puts the two repeaters the distance does not need side by side next to the lever and lays out the rest as 15 dust, repeater 4, 15 dust, repeater 3, 6 dust. Count the blocks and it comes to 2 + 15 + 1 + 15 + 1 + 6 = 40. Ask for less than the distance allows, 1 redstone tick over the same 40 blocks, and the tool says so and gives the fastest plan instead, which is 0.2 seconds.

Timings two sources agree on

Beyond repeaters, three components on the calculator's reference table have fixed delays that the wiki and crafty.gg state the same way. A comparator passes a change on after 2 game ticks, in either mode. A hopper waits 8 game ticks between item moves, which is where its 2.5 items a second comes from. TNT lit by fire or by a redstone signal explodes 80 game ticks later: four seconds, as long as ten repeaters on their last setting.

What this does not cover

Some delays stay off the table because the sources split. The wiki gives dispensers and droppers a delay of 4 game ticks, while crafty.gg's table says 0.1 seconds. For pistons the wiki separates a start delay, 0 or 1 game tick in Java depending on when in the tick the piston is powered and a fixed 2 in Bedrock, from the 2 game ticks the movement itself takes, while crafty.gg gives one figure of 3 game ticks. For observers the wiki describes a 2-game-tick pulse without a single delay figure, and crafty.gg gives both 0.05 seconds and one redstone tick per observer. The redstone torch is left out for a different reason: the wiki says it takes 2 game ticks to change state, and crafty.gg has no torch row to check that against. When two sources do not say the same thing, this site prints neither.

Two further limits. Every figure here is in game ticks, and the wiki's tick page is plain that a world which cannot keep up runs fewer than 20 of them a second, so lag stretches every delay in seconds while leaving the tick counts alone. And the planner models flat, straight lines and the delay the repeaters add. It does not model pulse shortening or stretching, Java's 0-tick and instant-repeater circuits, or Bedrock's two-phase alignment, all of which the wiki's repeater and redstone mechanics pages cover in detail.

Sources

Game and redstone ticks: the Minecraft Wiki's tick page and redstone mechanics page. Repeater settings and the half-second example: minecraft.wiki/w/Redstone_Repeater. Dust reach: minecraft.wiki/w/Redstone_Dust. Component timings: the wiki's comparator, hopper, TNT, dispenser, dropper, piston, observer and redstone torch pages. All were read 2026-09-12 and compared with the redstone tick calculator at crafty.gg/tools/redstone-tick. The arithmetic, the signal simulation and both tables above are asserted in tests/mirror_redstone-tick-calculator.py, which runs before every deploy.