Campsite Lighting Calculator

Campsite lighting quality depends on lumens (total light output) and how efficiently those lumens illuminate your space.

Lumens guide for camping:

• 50–100 lumens: Dim accent light, path marking
• 100–200 lumens: Comfortable reading, small tent interior
• 200–400 lumens: Full campsite table lighting
• 400–800 lumens: Bright campsite, cooking and socialising
• 800+ lumens: Very bright, search and emergency use

Coverage area formula (rough approximation): Radius (m) ≈ sqrt(lumens / (minimum lux × pi))

Where minimum useful lux for:

• Reading: 200 lux
• Campsite tasks: 50 lux
• General ambient: 10 lux

Battery life formula: Hours = battery capacity (Wh) / lamp power draw (W)

If your power bank is labelled in mAh rather than watt-hours, convert first: (mAh × voltage) ÷ 1000 = Wh. Most banks run at 3.7 V internally, so a 10,000 mAh bank holds about 37 Wh. Manufacturers print the mAh figure because it is the bigger number.

Why the coverage figure is smaller than you expect

Light falls off with the square of distance, so doubling the radius you want to light needs four times the lumens. That is the single most common surprise when people buy a camp lantern. A 300-lumen lantern that lights a 1.4 m radius for cooking will not light a 3 m radius by turning it up a bit. It needs roughly 1,350 lumens.

Two practical consequences. First, two 200-lumen lanterns placed apart beat one 400-lumen lantern in the middle almost every time, because you are covering two small circles instead of trying to stretch one. Second, hanging the light higher helps more than making it brighter. A lantern at head height spreads its output across the whole table; the same lantern sitting on the table lights the underside of your chin and blinds everyone.

A note on running time

Manufacturers quote runtime at the lowest brightness setting, which is usually a fraction of the headline lumens. A lantern advertised as “400 lumens, 20 hours” typically means 400 lumens for about three hours, or 20 hours at 40 lumens. Work out your real need from the calculator above, then check the runtime at that specific output rather than the number on the box.

Common camping light types:

Diffuser effect: A frosted lantern diffuser spreads light evenly but reduces effective lumens by 20–30%. Useful for ambient lighting; not ideal for focused task lighting.