Square Feet to Square Kilometers
Type a value in either box to convert between square feet and square kilometers. The factor is 9.2903e-08.
| Square Feet | Square Kilometers |
|---|---|
| 1 ft² | 9.2903e-08 km² |
| 2 ft² | 1.85806e-07 km² |
| 3 ft² | 2.78709e-07 km² |
| 5 ft² | 4.64515e-07 km² |
| 10 ft² | 9.2903e-07 km² |
| 25 ft² | 2.32258e-06 km² |
| 50 ft² | 4.64515e-06 km² |
| 100 ft² | 9.2903e-06 km² |
How to use
- Enter a value in the Square Feet field.
- The Square Kilometers figure appears immediately — no button to press.
- Typing in the Square Kilometers field converts back to Square Feet the same way.
- Use the reference table for the values that come up most often.
Square Feet to Square Kilometers formula
Converting square feet to square kilometers is a single multiplication by 9.290304e-08.
km² = ft² × 9.290304e-08
Why this factor: the square foot and the square kilometer are both defined against the square meter, so dividing one definition by the other gives 9.290304e-08 directly. Both definitions are set out in full below.
To go the other way, divide by 9.290304e-08 — or use the Square Kilometers to Square Feet converter, which is the same calculation reversed.
Worked example
Start with 50 ft². Multiply by 9.290304e-08 to get 4.64515e-06 km².
50 ft² × 9.290304e-08 = 4.64515e-06 km²
The converter above does this for any value you type, in either direction.
What is a square foot?
A square foot is the primary unit of floor area in the United States.
Definition: Exactly 0.09290304 square meter, following from the exact 0.3048 m foot.
Where it is used: US and Indian property listings, commercial leases, and paint and flooring coverage.
What is a square kilometer?
A square kilometer is the area of a one-kilometer square — one million square meters.
Definition: Exactly 1×10⁶ square meters. Note it is the kilometer that is squared, not the prefix applied to a square meter.
Where it is used: City, national park and country areas, population density, and land cover statistics.
Square Feet vs Square Kilometers
The square foot is an imperial unit while the square kilometer is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many square kilometers are in a square foot?
One square foot equals 9.290304e-08 square kilometers.
What is the formula to convert square feet to square kilometers?
Multiply the number of square feet by 9.290304e-08. To reverse it, divide by 9.290304e-08 instead.
How do I convert square kilometers back to square feet?
Divide by 9.290304e-08, which is the same as multiplying by 10763910.4.
How many square kilometers are in 10 square feet?
10 ft² works out to 9.2903e-07 km².
How is the square foot defined?
Exactly 0.09290304 square meter, following from the exact 0.3048 m foot.