Convert Inch per Minute to Beaufort Scale (in/min → Bft)

Converting inches per minute to Beaufort is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in inches per minute

   Start with the number of inches per minute (in/min) you want to convert.
2. 2
   Multiply by 0.000423

   The conversion factor from in/min to Bft is 0.000423. Multiply your value by this number.
3. 3
   Read the result in Beaufort

   The result is your value in Beaufort (Bft).

Multiply the value in inches per minute by 0.000423. For the reverse direction, multiply by 2,364.0662.

• ✓1 in/min = 0.000423 m/s = 0.0254 m/min.
• ✓CNC: lower in/min for harder materials; higher for softer.
• ✓Always match tool speed and material — too fast breaks bits.

• ✗Using mm/min and in/min interchangeably in CNC — 25.4× difference.
• ✗Treating 100 in/min as fast — only moderate in CNC.
• ✗Confusing feed rate with spindle RPM.

What is the Inch per Minute?

Inches per minute is the American standard feed-rate unit for CNC machining, 3D printing, milling machines, and precision manufacturing. Machinists program tool feed rates in IPM (inches per minute) — typical values range from 5 to 100 IPM depending on material and tool. American machine controllers (Fanuc, Haas, Mazak) default to inches per minute when set to imperial mode. 3D printer feed rates are also commonly specified in IPM in US-built machines. The unit relates to inches per second (60 ipm = 1 ips), mm per minute (1 ipm = 25.4 mm/min — the metric machinist equivalent), and feet per minute (12 ipm = 1 fpm). Manufacturing CAM (computer-aided manufacturing) software allows switching between IPM and metric mm/min depending on machine controller setup.

• CNC milling and turning feed rates
• 3D printer head movement
• Some US industrial flow specifications

What is the Beaufort Scale?

The Beaufort scale is an empirical wind-force scale ranging from 0 (calm) to 12 (hurricane), developed in 1805 by British Royal Navy Admiral Francis Beaufort. Originally designed for ships at sea, the scale was based on observed effects: 'How much sail can my ship safely carry?' Modern versions describe both observed effects on land and sea and corresponding wind-speed ranges. Force 0 is dead calm (under 1 km/h), Force 6 is 'strong breeze' (39–49 km/h, large branches in motion), Force 10 is a 'whole storm' (89–102 km/h), and Force 12 is hurricane (over 118 km/h). The conversion to numeric speeds follows v = 0.836 × Bft^1.5 m/s. Sailors, meteorologists, and shipping forecasts still use the Beaufort scale because its descriptive nature is intuitive: 'Force 8 gale' immediately conveys conditions to anyone familiar with the scale.

• Marine weather forecasts
• Sailing and offshore navigation
• Historical weather records