Crossword Difficulty Calculator

Work out crossword difficulty instantly with clear inputs, formula shown and shareable results.

About Crossword Difficulty Calculator

The index combines openness, which is one hundred minus the block density, with average answer length, since both longer answers and fewer blocks reduce the crossing help available. American-style grids run about 16% blocks with heavy interlock while British cryptics use closer to 25%, which is why the two feel so different to solve.

Formulas

Block density

density % = blocked squares / total squares x 100

Answer count

answers = fillable squares x 2 / average answer length

Worked example

With the default values below, Crossword Difficulty Calculator returns Difficulty index (0-100) of 70.67. Change any input above and every figure here is recalculated in your browser.

Inputs used

Grid sizeaccepts 3–30: 15
Blocked squaresminimum 0: 38
Average answer lengthminimum 1: 5.2

Results

Difficulty index (0-100): 70.67
Share of blocked squares: 16.89%
Estimated number of answers: 72
Fillable squares: 187

Step by step

1Values used
2Block density
3Answer count
4Difficulty index (0-100)= 70.67
5Share of blocked squares= 16.89
6Estimated number of answers= 72
7Fillable squares= 187

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Crossword Difficulty figure worked out?

density % = blocked squares / total squares x 100. The index combines openness, which is one hundred minus the block density, with average answer length, since both longer answers and fewer blocks reduce the crossing help available.

Why does this matter?

American-style grids run about 16% blocks with heavy interlock while British cryptics use closer to 25%, which is why the two feel so different to solve.

What do I need to enter?

Enter grid size, blocked squares, average answer length. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.