Outdoor candle lantern fuel nights
Estimate how many evenings a liquid-fuel or measured candle supply will last from fuel ounces, burn rate, and hours per night for Prince William County porch lantern paths.
nights = total_fuel_oz ÷ (oz_per_hour × hours_per_night)
When to use
Use this for oil lanterns, liquid paraffin cells, or when you weigh/measure candle fuel for a nightly porch path.
Hours per night should match your timer or typical dusk-to-bed window — not the full 24 hours.
Sum of bottle ounces or candle fuel mass as oz.
Check the lantern or candle label; ~0.3–0.8 oz/hr common.
Timer window each evening.
Split the fuel pool across this many burners.
Worked example
Example defaults — 32 oz fuel; 0.5 oz/hr; 5 hr/night; 4 lanterns.
Nightly burn = 0.5 × 5 × 4 = 10 oz; nights = 32 ÷ 10 = 3.2 → about 3 full evenings.
Buy another quart before a weekend open-house if you need a full week.
Second example: one input changed
From the defaults (Total fuel on hand (oz) = 32; Burn rate (oz per hour) = 0.5; Hours lit per night = 5; Lanterns sharing this fuel = 4), the calculator shows:
Fuel burned per night: 10.00 oz
Nights of supply: 3.2
Whole evenings you can finish: 3.
Now raise Total fuel on hand (oz) from 32 to 48 and keep the other entries. The result becomes:
Nights of supply: 4.8
Whole evenings you can finish: 4.
Comparing the two runs tells you how sensitive the answer is to that one measurement. If a small change in it swings the result a lot, measure it twice.
Limits / assumptions
Units: fuel and burn rate in fluid ounces; hours per night.
Assumptions: steady burn rate; all lanterns lit the same hours; no wind gust fuel waste.
Not a substitute: open-flame safety rules, HOA flame bans, or LED lantern equivalents.
Never leave open flames unattended. Prefer LED lanterns near walkways, dry mulch, or windy porches. Keep fuel away from kids and pets.
FAQ
LED lanterns instead?
Skip fuel math — use timer-on-hours or window-candle timer nights for schedules.
Windy nights?
Raise oz/hr slightly or shorten hours; shields help.
Mixed lantern sizes?
Sum each lantern’s nightly ounces, or run the tool once per size.