Feet to Miles (ft → mi) – Exact Relationship Guide
Core idea: 1 mile = 5280 feet (defined). Therefore 1 foot = 1/5280 mile ≈ 0.00018939394 mi. Multiply feet by 0.00018939394 (or divide by 5280) to get miles. Reverse: multiply miles by 5280 to get feet.
Formulas
mi = ft ÷ 5280mi = ft × 0.00018939394 (decimal form)ft = mi × 5280- Bridge via meters (exact):
ft × 0.3048 / 1609.344 = mi (simplifies to ÷5280).
Quick Values
| Feet | Miles | Comment |
|---|
| 100 | 0.018939 | Small lot span |
| 1000 | 0.18939 | ≈0.19 mi |
| 2640 | 0.5 | Half mile |
| 5280 | 1 | One mile |
| 10560 | 2 | Two miles |
| 10000 | 1.89394 | From example |
Worked Example
Example: Convert 10,000 ft to miles.
mi = 10,000 ÷ 5280 ≈ 1.89393939 mi → rounded to 1.89394 mi (5 decimal places).
Where This Conversion Is Used
- Running / walking distances reported in miles but measured in feet on-site.
- Surveying & mapping legacy imperial field notes.
- Road signage planning and asset inventory conversions.
- Aviation obstacle clearance (feet) vs published route distances (miles).
Accuracy & Tips
- 5280 is exact—no rounding until you choose decimal places.
- Fast head estimate: feet ÷ 5000 ≈ miles (overestimates by ~5.6%). Refine by subtracting 6%.
- Half‑mile marker is 2640 ft; quarter mile 1320 ft.
- For higher precision keep at least 6 decimal places in intermediate steps.
More Examples
| Feet (ft) | Miles (mi) | Exact Fraction of Mile |
|---|
| 1320 | 0.25 | 1/4 |
| 7920 | 1.5 | 3/2 |
| 21120 | 4 | 4 |
| 26400 | 5 | 5 |
| 31680 | 6 | 6 |
FAQ
- Why exactly 5280 feet? Based on the definition: 1 mile = 8 furlongs, 1 furlong = 660 ft → 8 × 660 = 5280.
- How many feet in 3.2 miles? 3.2 × 5280 = 16896 ft.
- How many miles is 2500 ft? 2500 ÷ 5280 ≈ 0.47348 mi.
- Best mental shortcut? Use ft ÷ 5000 then subtract about 6% for a closer result.
Exact relationships used; decimal forms rounded for clarity.