Watch Unit Converter

Convert between common horological measurement units. Type in any field.

Length

1 ligne (''') = 2.2558 mm. Used for movement and case sizing.

Common Movement Sizes

Standard movement diameters in the watch industry.

LignemmCommon Calibers
8'''18.05Ladies' movements
10½'''23.69Small men's (vintage)
11½'''25.60ETA 2824, Sellita SW200
12'''27.07Miyota 9015
13'''29.33Valjoux 7750
13¼'''29.90ETA 6497/6498
16'''36.09Pocket watch movements
18'''40.60Large pocket watch

Watch Screw Threads

Common thread sizes used in watch cases and movements.

SystemSizeDiameter (mm)Pitch (mm)
Swiss TAPTAP 0.500.500.10
Swiss TAPTAP 0.600.600.10
Swiss TAPTAP 0.700.700.125
Swiss TAPTAP 0.800.800.15
Swiss TAPTAP 0.900.900.15
Swiss TAPTAP 1.001.000.175
Swiss TAPTAP 1.201.200.175
Swiss TAPTAP 1.401.400.20
Swiss TAPTAP 1.601.600.20
MetricM1.01.000.25
MetricM1.21.200.25
MetricM1.41.400.30
MetricM1.61.600.35
MetricM2.02.000.40
BA12 BA1.300.25
BA10 BA1.700.35
BA8 BA2.200.45
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