Measure the two wheels and the distance between hubs. This returns the closed-loop blade length for a two-wheel saw. No account, no network.
A two-wheel band saw is the same geometry as an open belt on two pulleys. The blade runs two straight spans plus an arc around each wheel.
L = 2C + π(D1 + D2)/2 + (D1 − D2)² / (4C)
D1, D2 = wheel diameters · C = center distance · all in the same unit.
When the wheels are equal, the last term is zero and this is just L = 2C + πD. Measure diameters on the tire where the blade rides. Measure C at mid-tension so the saw still has take-up in both directions.
| Wheels | Centers | Length |
|---|---|---|
| 14 in / 14 in | 24 in | 91.98 in (2 336 mm) |
| 14 in / 14 in | 30 in | 103.98 in |
| 14 in / 12 in | 24 in | 88.88 in |
| 350 mm / 350 mm | 500 mm | 2 099.6 mm |
Those four rows were computed independently and match this page. A 14 in saw with a riser block and ~30–31⅛ in of center travel lands near 104–106 in, which is the usual 105 in replacement blade for that setup.
Measure from the center of the upper axle to the center of the lower axle. A steel rule on the hub faces is fine if both hubs are the same thickness. Set the tension adjuster in the middle of its travel before you measure, unless you are capturing the min/max range.
Enter both diameters. The (D1 − D2)² / (4C) term corrects the extra wrap on the larger wheel. For equal wheels that term is zero. Three-wheel saws are a different path; use an old blade or the manual instead of this formula.
No. Blades are sold in standard lengths, and the tensioner covers a band of maybe ½–2 in depending on the saw. Order the nearest catalog length that sits inside your min–max range. If you only have one center measurement, round to the nearest ½ in (or 10 mm) and confirm against the manual.
Yes, and it is often faster. Lay a used blade out straight, or hang it on two nails and measure the loop. This calculator is for when the old blade is gone, broken short, or you do not trust the stamp.
Use whichever you measured in. Mixing units will give a useless number. The result is also shown in the other unit so you can read a metric catalog from an inch tape, or the reverse.
Use the chart in the manual if you have it. Charts skip odd wheels, riser blocks, and aftermarket tires. Measuring the machine you actually own is the reliable method when the plate is missing or the saw was modified.