Key takeaways
- Lunch box searches climb every August as families and office workers restock for the new term. Bento-style boxes with sealed compartments are the ones people keep buying.
- For hot meals you need an insulated food flask, not a plastic bento. A vacuum flask keeps soup or pasta warm until lunch; a normal box does not.
- Stainless steel costs more but survives school bags and dishwashers far longer than plastic. Plastic is lighter and cheaper if you replace it often.
- Our picks run from £6 to about £30, so there’s a sensible option whether it’s for a five-year-old or a desk lunch.
Every year the same thing happens in late August: the summer holidays wind down, the “what’s in my lunch bag” videos start doing the rounds again, and lunch box searches shoot up as parents and commuters get organised. Packed lunches also just save money, and with eating out still pricey, more people are bringing food from home. The trouble is the shelves are full of boxes that leak, crack, or can’t keep anything warm. We went through what’s actually selling on Amazon UK right now and picked six that do the job, for kids and adults.
How we picked these
We started from what’s trending on Amazon UK Best Sellers in food storage and back-to-school, then filtered by the things that actually matter day to day. Leakproofing came first, because a box that spills yoghurt through a school bag gets thrown out fast. We looked for genuine compartment separation so wet and dry foods stay apart, materials that handle daily washing, and a size that suits the eater rather than one giant box for everyone. We also split out hot-food needs, since a flask and a bento are different tools. Prices and specs were checked on Amazon UK at the time of writing and will move around.
| Lunch box | Best for | Material | Around |
|---|---|---|---|
| Citron Kids Lunch Box 700ml | Younger kids | Plastic | £22 |
| Sistema Bento Box Lunch 1.65L | Budget | Plastic | £6 |
| Moonmoon Stainless Steel 1.4L | Longevity | Stainless steel | £24 |
| Milu Food Flask 450ml | Hot food | Insulated steel | £17 |
| monbento Original | Desk lunches | Plastic | £30 |
| Stackable 3-Layer 98oz | Big appetites | Plastic | £20 |
The best lunch boxes to buy in the UK
Citron Kids Lunch Box 700ml
Best for younger kidsBuilt for small hands, with easy-open clips and separated wells so grapes don’t roll into the sandwich. The 700ml size suits primary-age portions, and the leakproof seal holds up to being tipped about in a book bag. Parents like that it wipes clean and goes in the dishwasher.
The catch: it’s pricey for the capacity, and once children want bigger portions they’ll grow out of it.
700ml · leakproof compartments · around £22
Check price on Amazon →Sistema Bento Box Lunch 1.65L
Best budget pickA well-known name doing the basics for about the price of a meal deal. You get removable containers inside a main box, so you can keep yoghurt or dressing apart from the rest, and the whole thing is dishwasher and microwave safe. Good starter box for older kids and anyone testing whether packed lunches will stick.
The catch: the inner pots seal well but the outer lid isn’t fully leakproof, so don’t pack runny soup and lay it flat.
1.65L · removable pots · around £6
Check price on Amazon →Moonmoon Stainless Steel Lunch Box 1.4L
Best for longevityIf you’re tired of replacing cracked plastic, this is the upgrade. The 1.4L steel body shrugs off knocks, doesn’t stain from tomato or curry, and has no plastic touching the food beyond the seals. It’s a sensible middle size for a teenager or an adult lunch, and it should last years rather than terms.
The catch: steel can’t go in the microwave, so you’ll be eating cold or reheating on a plate.
1.4L · BPA-free, dishwasher safe · around £24
Check price on Amazon →Milu Food Flask 450ml
Best for hot foodThis is the one to get if you want warm food at lunchtime. It’s a vacuum-insulated stainless steel flask that keeps soup, stew, pasta or porridge hot for hours, and it’s wide enough to eat straight from. Fill it with boiling food in the morning and it’s still warm by midday, which no plastic bento can do.
The catch: it’s one round pot, so it’s for a single hot dish rather than a compartmented meal.
450ml · vacuum insulated, leakproof · around £17
Check price on Amazon →monbento Original
Best for desk lunchesA tidy two-tier bento made in France that looks the part on an office desk. The two stacked compartments seal properly, so you can carry it upright in a bag without a spill, and the design is compact enough to fit a normal lunch without bulk. It’s the kind of box people actually keep using rather than shoving in a drawer.
The catch: the price is high for the capacity, and it’s a smaller portion suited to adults, not big meal-preppers.
1L, two tiers · leakproof, microwave safe · around £30
Check price on Amazon →Stackable 3-Layer Bento 98oz
Best for big appetitesThree stacking layers give you a lot of room, so this suits meal-preppers, teenagers with big appetites, or anyone packing a full lunch plus snacks. It comes with a spoon and fork, the layers clip together, and you can leave a tier at home on lighter days. Good value for the capacity.
The catch: fully loaded it’s heavy and tall, so it won’t slip into a slim bag.
3 layers, ~2.9L · cutlery included · around £20
Check price on Amazon →Frequently asked questions
Are stainless steel or plastic lunch boxes better?
Steel lasts far longer, doesn’t stain or hold smells, and takes daily knocks without cracking. Plastic is lighter, cheaper, and can usually go in the microwave. If you reheat at work, plastic is handier; if you want one box for years, steel wins.
How do I keep food hot in a lunch box?
A normal bento won’t keep food warm. You need a vacuum-insulated food flask. Warm the flask with boiling water first, tip it out, then add piping-hot food and seal it straight away. That way it’s still warm at lunchtime.
What size lunch box does a child need?
For primary-age children, something around 600 to 800ml is usually enough for a sandwich, fruit and a snack. Older kids and teenagers tend to want 1L or more. It’s better to slightly under-size than to send a huge box back half full every day.
Are these lunch boxes leakproof?
The dedicated bento boxes and the flask here seal well for everyday packed food. The budget Sistema is best kept flat and away from very runny liquids. As a rule, check whether the maker says “leakproof lid” rather than just “leakproof inner pots”.
Sources
Prices and specifications checked on Amazon UK Best Sellers at the time of writing. General food-safety guidance on packed lunches from the Food Standards Agency.