What the calculator counts
3BV is the fewest left clicks needed to reveal every safe cell when the mine locations are already known. It is a board workload measure, not a prediction of how long a human should take.
- Every connected zero region is one opening. One click reveals that region and the numbered border around it.
- Every remaining safe cell outside those revealed borders needs its own click.
- The number of openings plus those individual safe cells is the board's 3BV.
A worked calculation
| Measured part | Count | Contribution |
|---|---|---|
| Connected openings | 4 | 4 clicks |
| Safe cells outside every opening border | 126 | 126 clicks |
| Total | 130 3BV |
The workload map above lets you inspect the same calculation on your own layout. Cyan cells are revealed as part of an opening. Purple cells are the safe cells that contribute one additional unit each.
Read the number without overrating it
Two boards with the same dimensions and mine count can have very different 3BV values. Large open areas reduce the minimum click workload. A fragmented board leaves more numbered cells to clear separately. This makes 3BV useful when raw time alone hides how much board work was present.
It still does not measure every kind of difficulty. Awkward patterns, mouse travel, recognition time, and forced guesses are not encoded in the total. For a completed run, pair it with 3BV/s and efficiency. The efficiency guide explains how those measures behave during play.
Metric notes
What is 3BV in Minesweeper?
3BV is the minimum number of left-clicks needed to clear a board with perfect play. Every opening (a connected region of zero cells) counts as one click, and every remaining safe cell that is not part of an opening counts as one more.
How do you calculate 3BV/s?
Divide the board's 3BV by your finishing time in seconds. A 150 3BV Expert board cleared in 75 seconds is 2.0 3BV/s.
What is Minesweeper efficiency?
Efficiency is 3BV divided by the number of clicks you actually used, as a percentage. Using exactly 3BV clicks is 100%. Chording can push efficiency above 100% because one chord can do the work of several clicks.
Use the result
Compare a finished run with the live time checker, study click reduction in the efficiency guide, or test another layout after an Expert game. The tools desk explains which measurement fits each question.