When looking for a new flashlight, you'll notice how central lumens are in marketing materials. Lumens measure light output, but are they really that important? And what does 300 lumens even mean?

In this article, we're going to answer all your lumen output questions so you can purchase the right flashlight for your needs.

What The ANSI FL1 Standard Means For Your Flashlight

In the past, purchasing a new flashlight was even difficult because there were no industry standards. Every manufacturer had their own (favorable) testing methods. This situation changed with the introduction of the ANSI FL1 Standard.  Leading flashlight manufacturers gathered to produce a consistent standard, with transparent labeling to help consumers make informed choices.

Lumens (Light Output) Explained

The lumen output of a flashlight determines the amount of visible light sent out from the source. Given how efficient an LED flashlight bulb can be, using wattage was no longer a reliable metric - leading to the introduction of lumens as the standard measure of light output.

It's easy to think that lumens must equal brightness, but this is not necessarily the case.

Two 700 lumen flashlights from different manufacturers will have varying brightness. This difference  is because brightness is also affected by:

• Candela - center beam candle output- the measurement of light in a single direction
• Optics and Reflector - to gather and aim photons (narrow beam, or wide) - results can be variable based on the quality
• Battery Strength - a low battery will produce very different results to a fully charged battery
• Flashlight mode - white light, red light, UV light, flashing
• Testing & Rating - ANSI FL1 Standard is vastly superior to non-standard ratings

Photo credit to: Macanta Design Build Inc.. Lighting – LED & Lumens (Part 1).

You can see that there are a lot of factors that go into the actual flashlight beam, and that's not even considering other factors such as durability, weight, price, functionality, etc. We tried to cover every angle in our Flashlight Buyer's Guide.

Candela Rating Explained

While the lumen rating is agnostic about where the light is heading, the candela rating (also called "peak beam intensity") is the opposite: it determines how intense a flashlight beam is at the brightest point. The photon collecting and aiming properties of the flashlight's reflector and optics will play a big role in the candela rating.

The lumen and candela ratings combined will help buyers determine the best application for the flashlight.

Beam Distance Explained

The final FL1 Standard is beam distance, which speaks to the maximum distance that can be illuminated at a level of 0.25 lux (the brightness of a full moonlight on a clear night). It's important to recognize that the beam distance indicated on the label is likely not going to be usable in many practical situations.

If there is a specific distance you need to illuminate, we recommend a good rule of thumb is to halve the beam distance rating. For example, in practical terms, 100 meters (328 ft) is closer to 50 meters (164 ft).

How Many Lumens Does a Flashlight Need?

The desired light output depends on how you intend to use your flashlight. To help you find the proper lumens range, here are some use-cases with lumen projections.

Work Light (90-500 lumens)

Finding the right work light requires more scrutiny than shopping for a flashlight for the home. 

For professional mechanics, builders, oil rig workers, etc., a work light should be durable, versatile, and able to produce several brightness modes, depending on the task at hand.

The ability to widen the beam to light an area is as important as focusing the beam for detail-oriented work.

For a mechanic, a professional work flashlight doesn’t need over-the-top lumen output, but it must be able to light an area AND focus the beam for closer inspections. The UK 4AA LIGHTHOUSE has a perfect 140-lumen output. Thanks to its right angle adjustment mechanism and the ability to magnetically mount the flashlight, it is the ideal versatility to free up both hands. 

Whereas oil rig workers are looking for flashlights that can thrive in some of the most challenging conditions. A powerful lumen output is important, as are multiple light modes. A head-mount is a necessity. Waterproofing is a must. And intrinsic safety is non-negotiable. Our guide to the best flashlight for oil rig workers breaks it all down. 

General Purpose (50-100 lumens)

Every house should have an everyday carry flashlight. Whether it's to search the garden at night for a missing toy, scanning the attic, or reading when the power's out - a general-purpose flashlight is a handy tool to own. A 2x AA battery at 100 lumens should last between 5 and 10 hours.

Night Running and Camping (100-500 lumens)

Walking at night and camping requires more light output to navigate surroundings safely. A jog could end badly if you don't illuminate your path. You don’t want to run with anything too heavy; in fact, consider a quality headlamp as a flashlight alternative for truly unencumbered running. 

In an outdoor setting, a strong light (but not strong enough to blind your family!) is vital for scaring off wildlife, setting up camp, or helping to find a wandering child!

Back indoors, 300 lumens will enable you to light a room by bouncing the light off the ceiling. Just make sure you have rechargeable lithium-ion batteries as a 2x AA flashlight might only last 1-2 hours.

Tactical Flashlights (1200-2500 lumens)

Tactical flashlights are used by the military and law enforcement with the expectation that the flashlight could be used in self-defense. Powerful light output can be used to temporarily blind or disorient an assailant, giving the user a vital edge during a dangerous encounter.

A tactical flashlight should also light up an area by easily switching from spot to a flood beam.

Search & Rescue (3000+ lumens)

Search & Rescue requires a very high bar for flashlight specs. Flashlight manufacturers need to ensure waterproofing, durability, and flexible modes such as a red light and strobe mode.

Of course, light output is also incredibly important to illuminate an area and find people in need. A powerful flashlight beam, that most flashlights can't hope to achieve, is essential for this field.

Our brightest flashlight Aqualite MAX has an output of 3000 lm and is 100% waterproof. 

Conclusion

Flashlight performance can be determined by the ANSI FL1 Standard, although it's important to remember that even those maximum output metrics may be variable in real-world conditions.

Ultimately, it's essential to know what you need to achieve - what a tactical flashlight needs is very different from what you'd want for camping. Remember - a high lumen count may not make much difference for your need - in fact, it could even be counter-productive.

Consumers should also remember that the things that aren't on the label often make the biggest difference in determining what makes a good flashlight. Water resistance, build quality and durability, weight, and many other factors play a role.

If you have any questions, we're here to help.