Knots to km/h conversion chart: 1–30 knots and higher values
One knot equals 1.852 km/h. Find the knot value in the left column and read kilometres per hour on the right. The table lists every whole knot from 1 to 30, then selected higher values. It is a static reference: no GPS, location permission or calculation script is needed.
| Knots (kn) | Kilometres per hour (km/h) |
|---|---|
| 1 | 1.852 |
| 2 | 3.704 |
| 3 | 5.556 |
| 4 | 7.408 |
| 5 | 9.26 |
| 6 | 11.112 |
| 7 | 12.964 |
| 8 | 14.816 |
| 9 | 16.668 |
| 10 | 18.52 |
| 11 | 20.372 |
| 12 | 22.224 |
| 13 | 24.076 |
| 14 | 25.928 |
| 15 | 27.78 |
| 16 | 29.632 |
| 17 | 31.484 |
| 18 | 33.336 |
| 19 | 35.188 |
| 20 | 37.04 |
| 21 | 38.892 |
| 22 | 40.744 |
| 23 | 42.596 |
| 24 | 44.448 |
| 25 | 46.3 |
| 26 | 48.152 |
| 27 | 50.004 |
| 28 | 51.856 |
| 29 | 53.708 |
| 30 | 55.56 |
| 40 | 74.08 |
| 50 | 92.6 |
| 60 | 111.12 |
| 80 | 148.16 |
| 100 | 185.2 |
Convert a decimal value or reverse the calculation
Use the row that matches the original measurement
The table answers a lookup question, not a measurement question. If an instrument says 17 kn, read 31.484 km/h; if it says 17.5 kn, do not silently replace it with 17 or 18. Use the converter or multiply the decimal directly. Keep the original unit with any copied result so someone else can check which direction you converted.
Why the factor is 1.852
A knot is one international nautical mile per hour, and that nautical mile is exactly 1.852 kilometres. Multiply knots by 1.852 for km/h; divide km/h by 1.852 to reverse it. There is no extra multiplication by 60 because both speed units already refer to an hour. A nautical mile alone is a distance, not a speed.
Keep rounding until the final result
For 12.5 kn, the product is 23.15 km/h. For 17 kn it is 31.484 km/h, or 31.48 to two decimal places and 31.5 to one. The whole-number rows retain exact products, but their decimal places do not certify the precision of a wind forecast or GPS sensor. Preserve the unrounded value for further arithmetic and round only for presentation.
Avoid the tempting double-it shortcut
Doubling knots gives a quick overestimate, not an exact conversion. At 20 kn it suggests 40 km/h instead of 37.04, an excess of 2.96 km/h. Multiplying by 1.8 is closer but still gives only 36 km/h. Use the table or exact factor when copying a specification or checking a calculation rather than treating a mental shortcut as the recorded result.
Convert the unit without changing what was measured
A 15-knot wind converts to 27.78 km/h of wind; a boat speed of 15 knots gives the same numerical product but describes another quantity. Conversion cannot turn wind into boat speed or speed through water into speed over ground. Keep labels such as gust, sustained wind or GPS speed with the result. This chart supplies neither weather warnings nor a safe operating speed.
Choose a lookup, calculator or live reading deliberately
Use this table to scan several common values. Use the linked calculator for fractional input or reverse conversion. Use a boat instrument when you need a current observation rather than arithmetic. To estimate distance, time must also be known: maintaining 10 kn for half an hour gives 5 nautical miles, or 9.26 km, under that constant-speed assumption. Changing conditions make that an estimate, not a navigation plan.
| Condition or factor | What it means |
|---|---|
| 12.5 kn × 1.852 | 23.15 km/h |
| 17 kn × 1.852 | 31.484 km/h; about 31.48 km/h |
| 37.04 km/h ÷ 1.852 | 20 kn |
| 10 kn for half an hour | 5 nautical miles = 9.26 km at constant speed. |
Technical references: Nautical mile and knot definition.
Questions about the conversion table
How many km/h are 10 knots?
10 knots equal 18.52 km/h.
How many km/h are 30 knots?
30 knots equal 55.56 km/h.
Are the listed integer conversions rounded?
No. Up to three decimal places retain the exact products for the integer knot values shown. Measurement uncertainty is separate.
Can I use the same factor for wind?
Yes for the units, but keep the wind label and do not interpret the result as boat speed or a safety threshold.
Does the chart work without JavaScript?
Yes. The table and formulas are part of the page text. Interactive decimal conversion is on the separate converter page.