Speed Converter

This calculator converts speed between the four units most commonly used in New Zealand and internationally: kilometres per hour, miles per hour, metres per second, and knots. It matters because different fields use different units: New Zealand's roads are signposted in km/h, science and physics problems typically work in m/s, older vehicle imports and overseas material often use mph, and aviation and sailing measure speed in knots, one nautical mile per hour. Rather than looking up separate conversion factors, you simply type a value into any one of the four boxes, km/h, mph, m/s or knots, and the other three recalculate instantly using the standard conversion ratios, where 1 km/h equals 0.621371 mph, 0.277778 m/s and 0.539957 knots. There is no submit button and no rounding surprises; every field stays in sync as you type, so you can convert in either direction without hunting for a formula. The worked example on this page shows New Zealand's open road speed limit of 100 km/h, which comes out to roughly 62.1 mph, 27.8 m/s and 54.0 knots. Use it to check an overseas speed limit, work out wind or boat speed in knots, convert a running or cycling pace, or translate a physics answer from m/s into something more familiar. Because the conversions are fixed mathematical ratios, the figures you get back are exact, not estimates.

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