A field guide to the atlas

Quilt guides for sizing, piecing, and troubleshooting

Match a wrong result to seam allowance, finished or unfinished size, square-up technique, print scale, terminology, difficulty, or sizing.

What went wrong or what do you need to understand?

DifficultyQuilt blocks for beginners
Start with the lowest computed scores.
Technique floor and piece count
Sizing12 inch quilt blocks
Compare blocks that divide cleanly at 12 inches.
Same-scale block and cutting index
SizingQuilt block sizes
Compare clean steps, cuttable eighths, and refused sizes.
Clean, cuttable, or refused
Triangle familiesHalf square triangle blocks
Browse every HST-bearing block and its terminology.
Anatomy, methods, and block atlas
SizingFinished vs unfinished block size
Keep finished, sewn unfinished, and starting cuts distinct.
Finished, sewn, and starting measurements
Seam allowanceThe quarter inch seam allowance
See what the seam removes and test it.
Entered row and derived diagnosis
Square-upHow to square up a quilt block
Check and trim a pieced block.
Target, centre, and diagonal guides
Wrong resultWhy is my quilt block the wrong size?
Diagnose seams, printing, sizing, or an uncuttable target.
Symptom-to-test decision map
TerminologyQuilt block glossary
Look up the measurement and unit words used here.
Anatomy labels and definitions
Print scalePrinting quilt patterns at 100%
Calibrate the one-inch square before cutting.
Print-scale comparison
DifficultyQuilt block difficulty
Read the computed score and its method.
Piece count plus technique floor
Triangle familiesHalf square triangle chart
Print every HST starting square from one chart.
Three methods at thirteen sizes

Published 2026-08-01 · Last updated 2026-08-08

Need a calculator?

Move from explanation to an answer with the calculator directory. Choose a block size, unit-cutting, whole-quilt, or yardage tool and keep the worked result visible as you adjust it.