Article reviewed by Jesús Andrade, an electronics engineer with an MBA from ESIC. He combines 20 years’ experience developing emergency lighting and risk-prevention devices with a strong background in business management. Andrade is currently CTO at SVE Worldwide, a company specialising in industrial risk-prevention solutions.
Lighting plays a part in many of our daily activities, whether we need to brighten a room after dark or carry out everyday tasks such as cooking, working or studying. The amount of light we need depends on the space and what we’re doing.
But how many lumens should a battery-powered lamp have? There’s no single figure that works for every situation. A lamp designed to create a relaxing atmosphere has different lighting requirements from one used for reading or working.
One way to assess how much light a lamp produces is to look at its lumen rating, which appears in the technical specifications of many lighting products. The lumen is the unit used to measure luminous flux, taking into account how the human eye perceives light. It’s a useful indicator when deciding whether we need more or less light.
A rechargeable lamp for home use should also provide enough light for its intended purpose. That’s why, before buying a cordless lamp, it’s worth checking whether it can deliver the right amount of light for your needs.
Contents
What are lumens, and what do they tell us about a lamp?
The difference between lumens, lux and watts
How much light do you need for reading, working or ambient lighting?
LILAK: Rechargeable battery-powered lamps with enough lumens for everyday tasks
Frequently asked questions about how many lumens a battery-powered lamp needs at home
What are lumens, and what do they tell us about a lamp?
The lumen is a unit in the International System of Units (SI) used to measure the luminous flux emitted by a light source, taking into account the sensitivity of the human eye. It’s defined through its relationship with two other units: the candela (luminous intensity) and the steradian (solid angle). Put simply, lumens measure the total amount of visible light emitted by a source, while candelas describe its luminous intensity in a particular direction.
Commercially available battery-powered lamps usually state their light output in lumens. In many countries, light sources covered by energy information requirements must declare this figure, although the specific obligations depend on the type of product. If the information isn’t clearly shown in the product specifications, you can contact the manufacturer to find out the lamp’s luminous flux.
Some lamps are sold without a bulb, allowing you to choose the lumen output when you buy one separately. Where the light source is already built into the lamp, it’s important to check its lumen rating alongside any other features relevant to how you intend to use it.
The difference between lumens, lux and watts
Lumens are one of the main measurements to consider when deciding whether a lamp provides enough light for your needs. However, it’s also useful to understand two other important units used in lighting: lux and watts.
- Lux: Lux is another unit in the International System of Units. It measures illuminance, which is the amount of light reaching a surface. It’s directly related to lumens, as one lux equals one lumen per square metre. Lux helps us understand how well a particular surface is illuminated. For example, if we distribute 1,000 lumens evenly across an area of five square metres, we theoretically achieve 200 lux. In practice, the actual figure depends on how much light reaches the surface and how evenly it’s distributed. To increase illuminance, we may need more lumens or a more suitable distribution of light.
- Watts: The watt is also part of the International System of Units and applies not only to lamps and lighting but to all kinds of electrical devices. It’s the unit used to measure electrical power. For example, a bulb rated at 80 watts (W) consumes 80 watt-hours (Wh) of energy when operated for one hour. Although lamps aren’t usually among the biggest electricity consumers in a home, every little helps. If you’re looking to keep your electricity consumption under control, checking the wattage of a portable lamp can be worthwhile. However, it’s important to remember that watts measure power, while lumens measure luminous flux.
How much light do you need for reading, working or ambient lighting?
So far, we’ve looked at the main units used to measure lighting and which ones matter when choosing a lamp. But how much light do you actually need for reading, working or creating a particular atmosphere? We’ll use lumens as a general guide to estimate how much light may be suitable for common activities and help you choose a lamp that meets your needs.
| Use | Approximate lumens | Recommendations |
| 🛋️ Ambient lighting | 100–300 lm | Soft, supplementary lighting to create a cosy atmosphere. |
| 📖 Reading | 400–600 lm | Light directed towards the book, avoiding shadows and glare. |
| 💻 Studying and working | 400–700 lm | Suitable illumination across the desk and work surface. |
These figures are approximate and shouldn’t be treated as fixed requirements. Several factors affect how much light we need, including the distance from the light source, how the light is distributed, the existing lighting in the room and individual preferences.
How Many Lumens Do You Need for Ambient Lighting?
For ambient lighting, we recommend using 100 to 300 lumens as a general guide. This level of light can provide gentle, supplementary illumination without needing to be the main light source in the room. We often use this type of lighting when there’s already a brighter source available, such as a ceiling light, but we want to create a more relaxing and welcoming atmosphere.
How Many Lumens Do You Need for Studying and Working?
For studying and working, an approximate range of 400 to 700 lumens can be a useful starting point. However, it’s also important to consider the direction of the light, the distance from the lamp and the size of the area you want to illuminate, among other factors. The aim is to provide suitable lighting across your workspace without creating distracting shadows or uncomfortable glare.
How Many Lumens Do You Need for Reading?
If you’re looking for a comfortable reading light, a range of 400 to 600 lumens may be sufficient in certain conditions. It’s worth remembering that we read in different environments, such as bedrooms, where we may not need particularly bright ambient lighting but do need enough well-directed light to illuminate the pages of a book.
LILAK: Rechargeable battery-powered lamps with enough lumens for everyday tasks
At LILAK, we believe cordless lamps should adapt to the everyday needs of our homes. That’s why we design our rechargeable battery-powered lamps with different lighting modes, allowing users to adjust the amount of light to suit the activity, whether they’re reading, working or simply enjoying some gentle background lighting.
Our aim is to combine suitable light output for these everyday activities with the convenience of a wireless lamp that doesn’t need to remain permanently connected to the mains.
Frequently asked questions about how many lumens a battery-powered lamp needs at home
How Many Lumens Should a Lamp Have?
It depends on how you intend to use it: whether you want supplementary lighting, need to illuminate a particular spot or want to provide general lighting for a room. There are approximate ranges you can use as a guide, but the amount of light required also depends on how it’s distributed and the size of the area you want to illuminate.
Is 800 Lumens Too Bright for a Lamp?
It depends on what you need those 800 lumens for. If you’re using the lamp for gentle background lighting, it may be too bright, particularly in a small space. If you’re using it as a study light, it could be suitable, provided the light is distributed correctly and doesn’t cause glare.
What Is a Lumen?
The lumen is the unit in the International System of Units used to measure the luminous flux emitted by a light source, taking into account the sensitivity of the human eye. The more lumens a light source produces, the greater its total visible light output, although the amount of light reaching a particular surface also depends on how that light is distributed.