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What Size Lamp Shade Do I Need?

Find the right lamp shade size from your lamp base height and width with simple proportion rules for balanced table and floor lamps.

Direct answer

For most lamps, the shade height should land around two-thirds of the lamp base height and the shade diameter should be at least as wide as the base, often a little wider. If the bulb shows clearly or the lamp looks top-heavy, the shade is usually the wrong size.

lamp base height sets shade height and lamp base width sets shade diameter
Calculator

Lamp shade size calculator

Shade diameter
10-13"
Lamp base height
in
Lamp base width
in
Neck or harp height
in
Shade diameter
10-13"
Shade height
10-14"
Fit check
Standard neck height: most drum and tapered shades should hide the bulb cleanly

Use these ratios as a starting band, not a rigid law. The best shade usually hides the bulb, stays at least as wide as the base, and looks balanced from normal seated eye level.

Fast shade proportion rules

Shade height

About two-thirds of base height

Keeps the lamp from looking stubby or top-heavy

Shade diameter

At least as wide as the base

Makes the lamp read as balanced from the front

Bulb visibility

Bulb should usually stay hidden at eye level

Stops glare and awkward proportions

If in doubt

Slightly larger often looks better than too small

Undersized shades tend to look mean and expose the hardware

Why this topic is more about proportion than exact math

Lamp shades are one of the easiest places to over-trust a formula. The ratios matter, but so do the lamp silhouette, neck height, bulb shape, room scale, and how the lamp looks from a seated position, so the calculator gives a strong starting band instead of pretending every base wants one perfect shade.

Quick checks before you order a replacement shade

  1. 1Measure the lamp base height without the shade.
  2. 2Measure the widest part of the base from side to side.
  3. 3Check the neck or harp height so you can judge where the bulb will sit inside the new shade.
  4. 4View the lamp from normal seated eye level instead of only from above when you confirm the final fit.

FAQ

How do I know if a lamp shade is too small?

A shade is usually too small if the bulb shows clearly, the lamp looks top-heavy, or the shade is narrower than the widest part of the base when viewed from the front.

Should a lamp shade be wider than the base?

Usually yes. A strong starting point is a shade diameter at least as wide as the base and often a little wider, which tends to look more balanced in normal rooms.

Do floor lamps and table lamps use the same shade rule?

The same proportion ideas help, but floor lamps usually tolerate larger and deeper shades than compact table lamps. Always check the lamp from normal seated eye level before treating the ratio as final.

Sources & method

We reviewed these references while writing this answer. Figures are estimates — confirm safety-critical work with a professional. Last updated June 7, 2026.