Speed Calculator
Calculate Speed, Distance & Time - Multiple Units & Conversions
⚡ Pro Tips for Speed Calculations:
Speed = Distance ÷ Time - fundamental formula. Ensure distance and time in compatible units. Speed units vary by region: metric (m/s, km/h), imperial (mph), maritime (knots). Convert between units for consistency. Average speed requires total distance and total time, not average of speeds. Velocity includes direction; speed is magnitude only.
Calculate Speed from Distance and Time
✅ Speed Calculation Results:
Calculate Distance from Speed and Time
✅ Distance Calculation Results:
Calculate Time from Speed and Distance
✅ Time Calculation Results:
Speed Unit Converter
✅ Speed Conversion Results:
Speed Unit Conversion Factors:
| Unit | m/s | km/h | mph | ft/s | knots |
|---|---|---|---|---|---|
| 1 m/s | 1 | 3.6 | 2.236928 | 3.280840 | 1.943844 |
| 1 km/h | 0.277778 | 1 | 0.621371 | 0.911344 | 0.539957 |
| 1 mph | 0.44704 | 1.60935 | 1 | 1.466667 | 0.868976 |
| 1 ft/s | 0.3048 | 1.09728 | 0.681818 | 1 | 0.592484 |
| 1 knot | 0.514444 | 1.852 | 1.150779 | 1.687810 | 1 |
Speed Reference Data
Common Speed Examples:
| Activity/Object | m/s | km/h | mph |
|---|---|---|---|
| Average walking speed | 1.4 | 5 | 3.1 |
| Peak human running | 12.42 | 44.7 | 27.8 |
| Peak cheetah running | 33.53 | 120.7 | 75 |
| Car highway speed | 25 | 90 | 55.9 |
| Commercial airplane cruise | 250 | 900 | 560 |
| Earth orbital speed | 29,783 | 107,218 | 66,623 |
| Sun orbital speed | 251,000 | 904,000 | 561,000 |
| Speed of sound (sea level, 20°C) | 343 | 1,235 | 768 |
| Speed of light in vacuum | 299,792,458 | 1,079,252,848 | 670,616,629 |
Speed Formulas & Relationships:
Basic Relationship:
speed = distance / time
Rearrangements:
distance = speed × time
time = distance / speed
Average Speed:
average speed = total distance / total time
Acceleration:
acceleration = (final speed - initial speed) / time
speed = distance / time
Rearrangements:
distance = speed × time
time = distance / speed
Average Speed:
average speed = total distance / total time
Acceleration:
acceleration = (final speed - initial speed) / time
📚 Understanding Speed, Distance & Time
What is Speed?:
Speed measures how fast object moves. Defined as rate at which position changes over time. SI unit: meters per second (m/s). Speed is scalar quantity - magnitude only, no direction. Unlike velocity which includes direction. Measured using distance traveled divided by time elapsed.
Key Concepts:- Instantaneous Speed: Speed at specific moment (speedometer reading)
- Average Speed: Total distance divided by total time
- Constant Speed: Unchanging rate over period
- Variable Speed: Rate changes during journey
- Speed vs Velocity: Speed has magnitude; velocity has magnitude and direction
- Metric: m/s (SI standard), km/h (common)
- Imperial: mph (US/UK), ft/s (physics)
- Maritime/Aviation: knots (nautical miles/hour)
- Conversion: 1 m/s = 3.6 km/h = 2.237 mph
- Vehicle navigation: determine travel time for distance
- Sports analysis: track performance metrics
- Physics problems: motion and acceleration calculations
- Safety: speed limits based on distance stopping
- Fitness: pace tracking for running/cycling
❓ Frequently Asked Questions
How do you calculate travel time for a trip?
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Use formula: time = distance ÷ speed. Example: 300 km at 100 km/h = 3 hours. Account for speed variations (traffic, speed limits). Average speed typically less than highway speed for real-world trips. Add buffer time for stops, rest breaks, unexpected delays.
What's the difference between speed and velocity?
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Speed: scalar (magnitude only). Example: "driving at 60 mph." Velocity: vector (magnitude + direction). Example: "driving 60 mph northbound." For distance/time calculations, use speed. In physics requiring direction, specify velocity. Speed always positive; velocity can be negative.
How do you convert between speed units?
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Conversion factors: 1 m/s = 3.6 km/h = 2.237 mph. 1 knot = 1.852 km/h. Use consistent units throughout calculation. If distance in kilometers and time in hours, result naturally in km/h. Always verify unit consistency - common source of errors.
Why is knot used in aviation/maritime?
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Knot: nautical mile per hour. Historically convenient for ocean/air navigation. Nautical mile defined by latitude lines. 1 knot ≈ 1.852 km/h. International standard for sea and air traffic. Distinct from regular mile - always specify "knot" or "kn" to avoid confusion.
What's average speed vs current speed?
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Current speed: instantaneous rate at moment (speedometer). Average speed: total distance ÷ total time. Example: 60 mph average but speeds varied 0-80 mph during trip. Average smooths variations. Always use average for travel time estimation from total distance.
How fast is the speed of light?
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Speed of light: 299,792,458 m/s ≈ 300,000 km/s. Approximately 1,079,252,848 km/h. Universal speed limit - nothing faster in physics. Used in relativity calculations. Dramatically faster than sound (343 m/s): light ~900,000× faster than sound.
Can distance be covered without moving?
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No - distance requires motion. Zero speed = zero distance covered (or zero time). Speed by definition relates distance to time. Stationary object has zero speed. To cover distance, must move at non-zero speed for period of time.
Why is accuracy in units important?
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Unit mismatch causes calculation errors. Example: 100 km ÷ 50 hours ≠ 50 km/h (wrong calculation order). Mixing units: 100 kilometers ÷ 2 hours = 50 km/h (correct). Always verify units match in formula before calculating. Most calculation errors stem from unit confusion.