Chess Next Move Calculator
Paste a position as FEN and get the best move, an evaluation and the line the engine expects.
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What is this?
A Chess Next Move Calculator analyses a chess position and reports the strongest move it can find, along with an evaluation, the top candidate moves and the continuation it expects. Positions are entered as FEN, the standard one-line description used by every chess site.
How to Use the Chess Next Move Calculator
This tool analyses a chess position and tells you the strongest move it can find. Paste the position as FEN, choose how deep to search, and the engine plays out every legal move and reply to that depth, scoring the results.
It reports the best move, an evaluation in pawns, the top three candidate moves and the line it expects to follow. Positive evaluations favour White, negative favour Black, and "M3" means a forced mate in three.
1. Get the Position as FEN
FEN is the standard one-line description of a chess position. Lichess, Chess.com and most analysis boards let you copy it. It records the pieces, whose turn it is, castling rights and the en passant square.
2. Paste It In
Paste the FEN into the field and the board redraws immediately. If the text is not a readable position the board says so rather than drawing something misleading.
3. Or Load an Example
Pick one of the built-in positions to see the engine work - a back-rank mate in one, a hanging queen, a rook endgame or the Italian Game.
4. Choose the Search Depth
Depth 2 is instant, depth 3 is a good balance, and depth 4 looks further ahead but takes noticeably longer. Deeper searches find longer forcing sequences.
5. Read the Result
The best move is highlighted on the board. Below it you get the evaluation, the top three candidates and the expected continuation for each.
Key Formulas Used in the Calculator
Position Evaluation
Score=Material+Piece Placement(in centipawns)
Each piece has a value - a pawn 100, knight 320, bishop 330, rook 500, queen 900 - adjusted by where it stands. Knights score better in the centre, pawns for advancing, and the king for staying tucked away until the endgame.
Minimax with Alpha-Beta
Score=maxyour moves(mintheir replies)
You pick the move that gives the best result assuming your opponent then plays their best reply. Alpha-beta pruning discards branches already worse than something found earlier, which cuts the work enormously without changing the answer.
Quiescence Search
at the depth limit, keep following captures until the position is quiet
Without this the search can stop halfway through an exchange and report being a queen up on a move that actually loses one. Captures are followed to the end before the position is scored.
Reading the Evaluation
+1.00=one pawn of advantage for White
M3=mate in three
Evaluations are always given from White's point of view, so -2.50 means Black is better by about two and a half pawns. Anything inside roughly plus or minus 0.5 is level.
Benefits
Finds forced mates and tactics several moves deep
Highlights the recommended move directly on the board
Shows the top three candidate moves, not just one
Gives the expected continuation for each candidate
Reports evaluations in the standard pawn scale engines use
Detects checkmate, stalemate and drawn positions
Runs entirely in your browser - no position is sent anywhere
When & Where to Use
Checking whether you missed a tactic in a game
Finding the mate in a puzzle you are stuck on
Blunder-checking a candidate move before playing it
Studying which capture in an exchange is actually best
Understanding why a move you liked is not the strongest
Teaching how engines evaluate a position
Settling an argument about a position after a game
Who Should Use This Calculator
The Chess Next Move Calculator is for club players analysing their games, students working through puzzles, coaches demonstrating tactics, and anyone curious how a chess engine picks its move.
Tips to Get the Best Deal
Copy the FEN from your analysis board rather than retyping it
Check the side-to-move letter in the FEN - w or b changes everything
Deeper searches find longer forcing lines but take longer
An evaluation inside half a pawn is effectively equal
Look at the expected line, not just the move - it shows the idea
If the top candidates score alike, the position genuinely has several good moves
Engines evaluate; they do not explain. Work out why the move is good
Frequently Asked Questions (FAQs)
What is FEN?
Forsyth-Edwards Notation, a single line of text describing a chess position: the pieces rank by rank, whose turn it is, castling rights, the en passant square and the move counters. Most chess sites let you copy it in one click.
How does the engine choose a move?
It plays every legal move, then every reply, to the chosen depth, and scores the resulting positions by material and piece placement. It then picks the move that gives the best score assuming the opponent also plays well.
What does the evaluation number mean?
It is measured in pawns from White's point of view. +1.00 means White is a pawn better, -2.50 means Black is two and a half pawns better, and anything within about half a pawn is level. M3 means a forced mate in three moves.
Is this as strong as Stockfish?
No. This searches a few moves deep with a simple evaluation, which is enough to find tactics and catch blunders but not to match a modern engine. For serious analysis use a full engine.
Why does a deeper search sometimes change the move?
Because a shallower search cannot see far enough. A move that looks good three plies out can be refuted on the fourth, which is exactly why depth matters in forcing positions.
Is my position sent to a server?
No. The engine runs entirely in your browser, so the position never leaves your device.
Why does it say there is no move to play?
The position is already finished - checkmate, stalemate, insufficient material or a drawn repetition. The status line says which.
Pro Tips
Copy the FEN from your analysis board rather than retyping it.
Check the side-to-move letter in the FEN - w or b changes everything.
An evaluation inside half a pawn is effectively equal.
Look at the expected line, not just the move - it shows the idea.
Deeper searches find longer forcing lines but take longer to run.
This is a lightweight engine, not a substitute for Stockfish.