You find a lamp you love, carry it home, put it on the side table and something is off. It looks like a hat on a toothpick, or it crowds the table, or it disappears next to the sofa. Usually the lamp is fine. The sizes just don't fit each other, or don't fit the table underneath.
Designers use a few simple proportion rules to avoid this. They are guidelines, not laws, but they explain most of the "something is off" feeling. Play with the lamp below. It starts out deliberately too big, so you can see what each rule catches.
Everything is drawn to the same scale. Base height is from the table to where the shade starts. Shade width is the widest part of the shade.
The shade should be at least as wide as the base. A shade narrower than the widest part of the base looks squeezed. Most guides land on a shade that is slightly wider than the base, up to about twice as wide for a slim base. Much more than that and it looks like a lampshade wearing a lamp.
The shade should be about two thirds of the base's height. A tall shade on a short base feels top-heavy. A tiny shade on a tall base makes the bulb peek out. Roughly half to four fifths of the base height is a comfortable range.
The shade should be narrower than the table top. If the shade hangs over the edge, it gets knocked, and it leaves no room for a glass, a book or your phone. Aim for a few centimetres of table on each side.
The whole lamp should not be much taller than about one and a half times the table height. This one is the loosest. A tall lamp on a low table tips the balance of the corner. On a low table, go for a shorter lamp rather than a bigger table.
These numbers come from the way lighting shops and interior writers usually describe proportion. They are a starting point. A sculptural lamp with a huge shade can be lovely if the rest of the corner is calm, and a small lamp on a big surface is fine as part of a group.
Online lamp pages list the height and the shade diameter, and you can compare them with your own table in about two minutes.
Look at the lamp's page for the base diameter, the shade diameter and the total height. If the base width isn't listed, compare the product photos with the shade diameter.
Cosy is not about buying more. If a lamp feels wrong, there are cheap fixes. Swap the shade with one from another lamp or a second-hand one, since most shades are inexpensive and are sold separately in standard sizes. Raise a small lamp on a stack of books or a tray. Move a lamp that is too tall to a floor, shelf or console where it has room. Charity shops and second-hand listings are full of good lamp bases, and you can often find a shade that fits.
A few safety basics: check the maximum wattage printed on the lamp and never go above it. Choose a bulb that fits the shade without touching it, and keep fabric away from hot bulbs. Rewiring a lamp or fitting a new plug is a job for a qualified person.
At a small budget, the proportion matters more than the material. Pick a lamp that fits your table by the checks above, with a plain shade in a warm, light colour so the light looks soft. Standard fittings such as E27 or E14 mean you can swap the bulb or shade later.
At a mid budget, look for a base and shade that are designed together, so the proportions are already right, and for a fitting that suits a warm-white bulb in the 2700 K range.
At a higher budget, you are paying for materials and finish, such as natural rattan, glass or a solid base, and for a design that feels calm in a corner for years. Check the listed measurements before falling for the photos.
If your own lamps already pass the four checks, you don't need anything. If you are shopping, the picks below are examples at different budgets, not reviews. We haven't tried them. Check each one's measurements against your table before ordering.