📏 ft to ly — Foot to Light Year Converter

Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.

1 unit =
From
To
Formula 1 ft = 3.2216e-17 ly
UnitNameValue
0.001 ft3.222e-20 ly
0.01 ft3.222e-19 ly
0.1 ft3.222e-18 ly
1 ft3.222e-17 ly
5 ft1.611e-16 ly
10 ft3.222e-16 ly
50 ft1.611e-15 ly
100 ft3.222e-15 ly
1000 ft3.222e-14 ly

How to convert Foot to Light Year

Multiply the number of Foots by 3.2216×10-17 to get Light Years. Formula: ly = ft × 3.2216×10-17. Example: 10 ft × 3.2216×10-17 = 3.2216×10-16 ly. To reverse, divide Light Years by 3.2216×10-17 to get Foots.

Worked examples

Example 1
1 ft × 3.2216×10-17 = 3.2216×10-17 ly
1 Foot equals 3.2216×10-17 Light Year.
Example 2
5 ft × 3.2216×10-17 = 1.6108×10-16 ly
5 Foot equals 1.6108×10-16 Light Year.
Example 3
10 ft × 3.2216×10-17 = 3.2216×10-16 ly
10 Foot equals 3.2216×10-16 Light Year.
Example 4 — reverse
1 ly = 3.104×1016 ft
To convert back from Light Year to Foot, divide by 3.2216×10-17 or use the swap button above.

Foot to Light Year — reference table

Foot (ft)Light Year (ly)
0.001 ft3.2216×10-20 ly
0.01 ft3.2216×10-19 ly
0.1 ft3.2216×10-18 ly
0.5 ft1.6108×10-17 ly
1 ft3.2216×10-17 ly
2 ft6.4433×10-17 ly
5 ft1.6108×10-16 ly
10 ft3.2216×10-16 ly
20 ft6.4433×10-16 ly
50 ft1.6108×10-15 ly
100 ft3.2216×10-15 ly
250 ft8.0541×10-15 ly
500 ft1.6108×10-14 ly
1000 ft3.2216×10-14 ly
10000 ft3.2216×10-13 ly

Quick conversion tips

1
Multiply by 3.2216×10-17

To convert Foot to Light Year, multiply by 3.2216×10-17. Example: 10 ft = 3.2216×10-16 ly

2
Reverse: divide by 3.2216×10-17

To convert Light Year back to Foot, divide by 3.2216×10-17 (multiply by 3.104×1016). Use the swap button above.

3
Round number check

Start with 100 Foots = 3.2216×10-15 ly as your reference point. Scale up or down from there.

Where foot to light-year conversion is used

Extreme scale physics education

1 foot = 3.222×10⁻¹⁷ light-years. Physics educators use foot-to-light-year conversion to help US students understand the extraordinary scale difference between everyday measurement and cosmic distances.

Science outreach in the US

Science communicators expressing astronomical distances for American audiences convert from light-years to feet: "The Andromeda Galaxy is 2.5 million light-years away — that's 8×10²² feet, more than 80 sextillion feet."

NASA public communication

NASA press materials express spacecraft distances in both light-travel-time (seconds, minutes, hours) and feet/miles for US audiences — converting between the astronomical scale and familiar US customary units is routine.

Dimensional analysis education

US university physics courses use foot-to-light-year conversion in dimensional analysis problem sets — requiring students to chain 5–6 conversion factors across the full range of astronomical and US customary units.

Scale model planning

Educators designing scale models of the universe for US audiences build from feet to light-years: at 1 foot = 1 light-year scale, the observable universe (93 billion ly) would need a model 93 billion feet — 17.6 million miles — across.

Science fiction worldbuilding

US science fiction writers and game designers converting distances between light-years (for stellar travel) and feet (for human-scale descriptions) use this conversion when making space opera settings feel physically consistent.

Frequently asked questions

1 Foot equals 3.2216×10-17 Light Years. Multiply any Foot value by 3.2216×10-17 to get Light Years.
10 Foots equals 3.2216×10-16 Light Years. (10 × 3.2216×10-17 = 3.2216×10-16)
100 Foots equals 3.2216×10-15 Light Years. (100 × 3.2216×10-17 = 3.2216×10-15)
Divide Light Year by 3.2216×10-17 to get Foots. Or multiply by 3.104×1016. Use the swap button on the converter above for instant reverse conversion.
Formula: ly = ft × 3.2216×10-17. Example: 5 ft × 3.2216×10-17 = 1.6108×10-16 ly.
Yes — Unitafy is completely free. No signup, no ads, and no data sent to any server. All calculations run in your browser.
Yes. Once loaded, the converter works without internet. Install Unitafy to your home screen as a PWA for the best offline experience.

About Foot and Light Year

Foot (ft)

The Foot is a unit of Length measurement (symbol: ft). 1 ft = 3.2216×10-17 ly. Used in scientific and practical Length measurement applications.

Light Year (ly)

The Light Year is a unit of Length measurement (symbol: ly). It is part of an internationally recognised measurement system used alongside the Foot.

History & origin

The foot is one of humanity's oldest measurement units, used by ancient Egyptians, Greeks, and Romans — each with slightly different values. The English statute foot was standardised at 12 inches in 1305 under King Edward I. Its definition was refined multiple times over centuries, finally fixed as exactly 0.3048 metres under the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, and South Africa. Today the foot remains official in the US, UK (for road distances and aviation), and international aviation worldwide.

The light-year was not coined by professional astronomers — it first appeared in a German publication in 1851 written by Otto Ule as a way to make stellar distances comprehensible to general audiences. It equals the distance light travels in one Julian year: exactly 9,460,730,472,580.8 kilometres. Professional astronomers often prefer parsecs, but the light-year became the public's unit of choice for cosmic distance. One light-year equals about 63,241 astronomical units.

Common use: Foot to Light Year conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.