Over the Board · Oct 8, 2026 · 9 min
What Is Increment in Chess? The Official Wording, Notation and Sizes (2026)
Increment is time added to your chess clock with every move. Here is the exact FIDE and US Chess wording, how Chess.com and Lichess write it, the usual sizes and the rules it changes.
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What is increment in chess?
Increment is extra time added to a player's clock with every move, so a player who moves quickly builds time up instead of only spending it. The US Chess rulebook says the increment "is added to the main time each turn, regardless of the amount of time it took the player to move", and Chess.com writes it as the second number of a control: 5 | 5 means 5 minutes for the game with 5 seconds added after each move.
Everything on this page comes from the FIDE and US Chess rulebooks, the Chess.com and Lichess help pages and two clock makers' own documentation rather than first-hand use.
In everyday chess speech, increment, Fischer time and bonus time all name that same added-seconds idea. FIDE's own glossary is broader: it uses the word for seconds given in either delay or cumulative (Fischer) mode.
The official wording, side by side
FIDE's Laws of Chess (checked October 2026) define the term in their glossary, and the definition is broader than most players expect. There an increment is "an amount of time (from 2 to 60 seconds) added from the start before each move for the player", and the same entry continues: "This can be in either delay or cumulative mode." The added-time kind that most players mean has its own glossary name, cumulative (Fischer) mode, described as a player receiving "an extra amount of time (often 30 seconds) prior to each move."
US Chess, Chess.com and Lichess use the narrower, everyday meaning:
| Source | Term it uses | What the wording says |
|---|---|---|
| FIDE Laws, glossary | increment | Seconds added before each move, in either delay or cumulative mode |
| FIDE Laws, glossary | cumulative (Fischer) mode | An extra amount of time before each move, often 30 seconds |
| US Chess rulebook | increment, also "Fischer" and "bonus" | Added to the main time each turn, however long the move took |
| Chess.com Help Center | bonus seconds, increment | The second number of a time control |
| Lichess FAQ | clock increment | Counted forty times in the game-length estimate |
Because FIDE's word covers both mechanisms, the announced control is what tells you which one you are playing. FIDE's Article 6.3.1 requires exactly that: the moves, the periods and "any additional amount of time added with each move" must be specified in advance.
How increment is written
The notation changes with the venue, but the added seconds are always the last number:
- Chess.com uses a vertical bar. Its Help Center explains that the second number "indicates the bonus seconds added to your clock after each move," and that a control with no second number "has no increment (bonus time)." Its own example, 18 | 10, gives 18 minutes for the game with 10 seconds added after each move.
- Lichess uses a plus sign, as in the 5+3 example in its FAQ.
- US Chess flyers use "inc/ (or +)" for added time, with the seconds written after it. The rulebook's sample mixed control, 40/90,SD/30;inc30, reads as 40 moves in 90 minutes, then sudden death in 30 minutes, with 30 seconds added on every move.
- FIDE writes its sample classical control out in words: 40 moves in 90 minutes, then all remaining moves in 30 minutes, "plus 30 seconds cumulatively from move 1."
- Clock menus often avoid the word entirely. DGT's North American labels the mode "Bonus time per move ("Fischer")", and Chess Armory sells its budget clock on its "bonus time features and delay".
Increment versus delay in one sentence
US Chess states the difference more precisely than any summary: "The fact that the main time will never go above what it was at the beginning of a move with delay is what makes it different from increment." Under delay, FIDE's Article 6.3.2 holds the main clock still while a "fixed extra time" runs, and only then does the countdown begin. Under increment, the seconds you do not use stay on your clock, so a run of quick moves leaves you with more time than you had at the start. For setting either mode and the worked comparison, read our guide to delay, increment and Bronstein settings.
Why the increment changes a game's category
Every rating body needs one number to sort a game into blitz, rapid or classical, and each one counts the increment differently. These are the formulas and the worked examples they publish themselves:
| Who sorts the game | How the increment is counted | Their own worked example |
|---|---|---|
| FIDE Laws, rapid and blitz appendices | Base time plus 60 times any increment | Rapid needs that total to exceed 10 minutes and stay under 60 minutes |
| US Chess rating rules | Each second of increment or delay counts as one minute (mm+ss) | G/60 d/5 counts as 65 minutes |
| Chess.com Live | Assumes an average game of 40 moves | A 2-minute game with 12 seconds per move counts as 10 minutes and is rated Rapid |
| Lichess | Initial time plus 40 times the increment | 5+3 counts as 420 seconds |
Chess.com's example is the clearest illustration of why the per-move seconds matter. A base of 2 minutes looks like bullet, yet Chess.com's Help Center says that control "results in a Rapid (not Bullet or Blitz) game". The bands themselves also differ, so one control can land in different pools depending on who rates it. A plain 10-minute game shows this even without an increment: FIDE's blitz definition covers games of 10 minutes or less, while Chess.com rates games of 10 minutes and longer as Rapid. Keep that in mind before comparing an online rating with an over-the-board one. Our guide to every chess time control lists the common settings in each band.
How large increments usually are
FIDE's glossary bounds the per-move addition at 2 to 60 seconds, and its sample classical control adds 30 seconds from the first move. US Chess goes further and publishes recommendations by base time in its rule 5E, plus a standard value for Regular-rated (slow) events: "When used, standard increment is 30 seconds (Regular)."
| Base time per player | US Chess recommended increment or delay |
|---|---|
| 10 minutes or less | 2 seconds |
| More than 10 and less than 30 minutes | 3 seconds |
| 30 minutes or more, or a mixed or repeating control | 5 to 30 seconds |
Online, any value is possible: Chess.com's custom control has an "inc" field for the increment in seconds. For club practice, the US Chess bands are a sensible starting point because they are the settings US Chess recommends to tournament organizers.
Rules that change when an increment is in play
The added seconds are not only a clock setting. Several rules switch on or off with them:
- Scorekeeping. FIDE excuses a player with less than five minutes left from writing moves only when they do not have 30 seconds or more added per move. US Chess is blunter: "When the time increment or time delay is 30 or more seconds, players must keep score through the end of the game." With a 30-second increment, every move goes on the scoresheet, so bring a scorebook you are happy to write in quickly. Check price on Amazon
- Quickplay finishes. FIDE's Guidelines III "shall apply only to standard chess and rapid chess games without increment and not to blitz games". Inside those guidelines, a player with less than two minutes left may ask for an increment of an extra five seconds for both players.
- Insufficient losing chances. The US Chess claim procedure for a sudden-death finish (Variation 14H) "is not available for games in which a clock is being used with either the time delay or the increment properly set".
- Move one. US Chess puts the delay or increment in force starting at move one unless the control says otherwise, which matches FIDE's "from move 1" wording.
Setting increment on a physical clock
US Chess names "an increment capable clock" as the standard timer for any increment control, so for rated play you need a clock with the mode, usually labelled bonus or Fischer rather than increment. Two options from this site's offers:
- Chess Armory Digital Chess Clock. The maker describes a standard chess timer that also offers bonus time and delay, which covers both kinds of control. Check price on Amazon
- DGT North American. DGT lists "time, bonus, delay and U.S. Delay functions", but its own product page now marks the clock "Out of production"; Amazon still listed it in stock (checked October 2026). Check price on Amazon
Both clocks, plus the LEAP alternative, are compared in our 2026 chess clock comparison. For sets, boards and other gear, see our full shortlist.
Sources
- Laws of Chess (effective from 1 January 2023) — FIDE Handbook (checked October 2026)
- US Chess Federation's Official Rules of Chess, online edition (2026) — US Chess Federation (checked October 2026)
- How do time controls work on Chess.com? — Chess.com Help Center (checked October 2026)
- Why are there different ratings in live chess? — Chess.com Help Center (checked October 2026)
- Frequently Asked Questions — Lichess (checked October 2026)
- DGT North American — Digital Game Technology (DGT) (checked October 2026)
- Chess Armory Digital Chess Clock - Portable Timer with Tournament & Bonus Time Features — Chess Armory (checked October 2026)
FAQ
What does 15+10 mean in chess?
It means 15 minutes per player at the start, plus 10 seconds added after every move. Chess.com writes the same control as 15 | 10 and estimates it at 22 minutes per player, which puts it in its Rapid pool.
Is increment the same as Fischer time or bonus time?
In everyday use, yes: the US Chess rulebook says increment is also commonly known as Fischer and bonus, and DGT labels the mode "Bonus time per move". The exception is FIDE's glossary, where the word can also cover delay mode.
Does the increment apply from the first move?
Usually. US Chess sets it in force from move one unless the announced control says otherwise, and FIDE's sample classical control adds its seconds from move 1. Online, Chess.com adds the seconds after each move you complete.
Can my clock show more time than I started with?
With increment, yes, because unused added seconds stay on your clock. With delay, no: US Chess notes that the main time "will never go above what it was at the beginning of a move".
Do I have to keep score in a game with increment?
With 30 seconds or more per move, yes: US Chess requires score to be kept through the end of the game in sudden death, and FIDE's time-trouble exemption does not apply. With smaller increments, both federations excuse scorekeeping once a player is under five minutes.
