Knots to MPH Converter — Convert kn to mph (Exact: 1 kn ≈ 1.150779448 mph)
Professional knots (kn) to miles per hour (mph) converter for aviation and maritime operations. Uses the exact definitions (1 NM = 1,852 m; 1 mile = 1,609.344 m) ⇒ 1 kn ≈ 1.150779448 mph. Ideal for flight ops, ECDIS/SOG checks, dispatch, SAR planning, and telemetry.
Note: Uses 1 NM = 1,852 m and 1 mile = 1,609.344 m, so 1 kn ≈ 1.150779448 mph. Explore more in our speed converter web tool.
About Knots to MPH Conversion
In aviation and maritime contexts, knots (kn) are the operational standard because they reference nautical miles, which align with the Earth’s geometry and traditional charting. Many cross-industry audiences, regulators, and media in the United States, however, prefer miles per hour (mph). Converting kn → mph lets flight ops, bridge teams, shore-side analysts, and external stakeholders read the same speed figures unambiguously—whether that’s for ECDIS overlays, fleet dashboards, or incident reports.
The conversion is grounded in exact definitions: 1 nautical mile = 1852 meters and 1 statute mile = 1609.344 meters. Therefore, 1 kn = 1.150779448 mph. Using this exact factor (not rounded 1.15) helps maintain integrity when you’re validating telemetry against SOP thresholds, tuning planning tools, or documenting SAR estimates where small errors can propagate.
Knots to MPH Formula
Exact relationship
Use the factor method:
mph = knots × 1.150779448Example:
18 kn × 1.150779448 ≈ 20.71399 mphReverse calculation (mph → kn)
Divide by 1.150779448:
knots = (mph) ÷ 1.150779448.
What is a Knot?
A knot is one nautical mile per hour. Because nautical miles correspond to minutes of latitude, course legs, bearings, and ETAs computed in knots integrate seamlessly with aeronautical and marine charts, E6B/CR flight computers, and bridge procedures.
What is mph?
Miles per hour is the predominant land-transport and media unit in the United States. When sharing performance summaries, public statements, or cross-industry documents, converting kn → mph ensures clarity for U.S. stakeholders while preserving the exactness your operational data requires.
Step-by-Step: Converting kn to mph
- Obtain the speed in knots (SOG, STW, IAS, TAS, or GS).
- Multiply by 1.150779448.
- Label the result in mph. Choose rounding based on audience and SOPs (whole mph for press; 1–2 decimals for dashboards).
Example walkthrough (flight ops brief):
Input: GS (final) = 142 kn
mph: 142 × 1.150779448 ≈ 163.41269 mph
Note: Keep full precision internally; round outward-facing tables to one decimal if requiredCommon Conversions
Everyday checks for flight ops, bridge teams & SAR
| kn | mph |
|---|---|
| 5 | 5.75390 |
| 10 | 11.50779 |
| 12 | 13.80935 |
| 15 | 17.26169 |
| 20 | 23.01559 |
| 25 | 28.76949 |
| 30 | 34.52338 |
| 40 | 46.03118 |
| 50 | 57.53897 |
Precision, Rounding & Significant Figures
Operational rounding
Bridge/cockpit callouts commonly use whole knots; media and mixed-audience decks in the U.S. often prefer whole mph or one decimal. Keep the exact constant in your methodology so external reviewers can reproduce values precisely.
Consistent documentation
Standardize column names (e.g., speed_kn, speed_mph), convert once, and avoid multi-step rounding. Include a short footnote: “Conversion uses 1 kn = 1.150779448 mph (1 NM = 1852 m; 1 mi = 1609.344 m).”
Related Speed Converters
Quick Reference Table
| mph | kn |
|---|---|
| 10 | 8.68976 |
| 15 | 13.03464 |
| 20 | 17.37952 |
| 25 | 21.72440 |
| 30 | 26.06928 |
| 40 | 34.75904 |
| 50 | 43.44880 |
| 60 | 52.13856 |
| 80 | 69.51808 |
Frequently Asked Questions
How do you convert knots to mph?
Use the exact relationship between nautical miles and statute miles: mph = knots × 1.150779448. This follows from 1 NM = 1,852 m and 1 mile = 1,609.344 m, so 1 NM = 1.150779448 miles.
What is 1 knot in mph?
1 kn ≈ 1.150779448 mph. For quick mental math, 1.15 is often used; for flight/bridge paperwork and telemetry, prefer the exact constant.
Why do professionals use knots instead of mph?
Knots map to nautical miles, which align with latitude/longitude (1 NM ≈ 1 arc-minute of latitude). This keeps legs, bearings, ETAs, and chart work consistent with ECDIS and aeronautical charts.
Does wind or current affect the conversion?
No. Unit conversion is constant. Environmental factors change the measured speed (IAS/TAS/GS in air, STW/SOG at sea), but converting kn → mph always uses ×1.150779448.
What’s the difference between IAS, TAS, and GS in knots—and does it matter here?
IAS is indicated airspeed, TAS is true airspeed (density-corrected), and GS is ground speed (wind-corrected). All can be in knots; each converts to mph with the same factor.
What precision should I publish?
Dashboards often show one decimal; certification/analysis may keep full precision internally. Document your use of 1 kn = 1.150779448 mph to ensure reproducibility.
How do I convert back from mph to knots?
Divide by 1.150779448: knots = mph ÷ 1.150779448. The reverse tool is linked in the Related Speed Converters section.
Is 1 knot always equal to one nautical mile per hour worldwide?
Yes. Under international standards, 1 NM is exactly 1,852 meters, so 1 kn is globally consistent.
Can I cascade via km/h if needed?
Yes. kn → km/h uses ×1.852, then km/h → mph uses ÷1.609344. The direct factor (×1.150779448) is simpler and exact.
When would mph be preferred over knots?
U.S. media, road systems, and some regulatory or cross-industry reports use mph. Converting kn → mph helps non-nautical teams read the same data.
Tips for Working with Knots & MPH
- Always label whether a figure is IAS/TAS/GS (aviation) or STW/SOG (maritime) to avoid misinterpretation.
- Store precise values; round only for presentation. Note the constant (1 kn = 1.150779448 mph) in your methodology.
- When collaborating with land-side teams, include both kn and mph columns to minimize back-and-forth clarifications.
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