Blade-to-Miter-Slot Alignment Calculator
Published:
INFO
Evidence Level: Level 2 — Protocol Lab.
This calculator interprets dial indicator readings taken during a table saw blade-to-miter-slot alignment check. It does not measure the saw directly. Accuracy depends on using the same blade tooth at the front and rear positions, controlling dial indicator direction, and following the saw manufacturer’s adjustment procedure.
Use this tool to interpret dial indicator readings taken during a table saw alignment check. It calculates the deviation between the front and rear of the blade relative to the miter slot and helps you decide if adjustment is needed based on your chosen tolerance.
Calculator
How to take the readings
- Unplug the saw before attempting any setup or measurement.
- Mark one specific tooth on the saw blade with a marker.
- Mount your dial indicator in the miter slot, ensuring it rides smoothly and consistently.
- Position the marked tooth at the front of the throat plate opening.
- Take the front dial indicator reading (you can zero the dial here).
- Rotate the blade so the marked tooth moves to the rear of the throat plate opening.
- Slide the dial indicator back and take the rear reading.
- Enter both readings into the calculator to check your alignment.
How to read the result
Within target: The difference between the front and rear readings is smaller than the tolerance target you selected. The blade reads parallel to the miter slot for this protocol check.
Slightly outside target: The deviation is larger than your target but still relatively small. You may want to double-check your measurement setup (indicator seating, dust in the miter slot) before loosening any trunnion bolts.
Outside target: The deviation is more than twice your selected tolerance. Confirm the reading, and if it is consistent, follow your saw manufacturer’s manual to adjust the trunnions or table.
Limitations
This calculator only compares front and rear dial indicator readings. It does not separate blade runout, arbor runout, tooth variation, miter slot wear, or indicator setup error. For best results, mark one tooth, use that same tooth at front and rear, keep the indicator carriage consistently seated in the miter slot, and repeat the measurement before adjusting the saw.
Related WoodGearLab guides
- Read the full blade alignment protocol
- Understand table saw runout
- Check fence alignment after blade alignment
- Kickback Mechanics
Found an issue with this calculator?
WoodGearLab calculators are built from simplified mechanical models and conservative assumptions. If a result looks wrong, a unit conversion behaves strangely, or a real-world measurement does not match the interpretation, send us a note.