How many half pans does a 5ml tube fill?

A standard 5 ml tube fills approximately 3 half pans (accounting for 10% shrinkage during drying). A 14 ml tube fills about 8.4 half pans. This makes tubes significantly better value than buying individual pans.

Why does the paint shrink?

Tube watercolour contains water and humectants (like glycerin) that partially evaporate as the paint dries in the pan. Expect about 10% volume reduction. The remaining dry paint is denser and more concentrated.

How do I fill pans from tubes without cracking?

Squeeze thin layers (about 1-2 mm) and let each layer dry completely before adding the next. Build up 3-4 layers over about a week. Thick single fills crack as they dry. Work in a dust-free area.

What tube sizes are available?

Common watercolour tube sizes: 5 ml (standard), 8 ml (some brands), 14 ml (large), and 37 ml (studio size). Artist grade is usually 5 or 14 ml. Student grade often comes in 8 or 12 ml tubes.

Is it cheaper to buy tubes or pans?

Tubes are almost always cheaper per ml. A 5 ml Winsor & Newton tube costs roughly the same as a half pan (1.5 ml) — making tubes over 3x better value. Buy your most-used colours in tubes and refill pans yourself.

ArtCalcs

Tube Volume Calculator — Tubes to Pans Conversion

Work out how many half pans a tube of watercolour paint will fill.

Tube Size

Pan Type

Number of Tubes

How We Calculate This

How Tube to Pan Conversion Works

Pans filled = (Tube volume x 0.9 shrinkage) / Pan volume

The total tube volume is reduced by 10% for drying shrinkage, then divided by the pan volume (1.5 ml for half pan, 3 ml for full pan). Fill pans in 3-4 thin layers over several days to prevent cracking.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.