About this tool
The Aquarium Glass Thickness Calculator is a free, in-browser tool that estimates the minimum safe glass thickness for a DIY aquarium build from the water height and the dimensions of each vertical pane. Water pressure is greatest at the base, P = ρ·g·H, with ρ = 1000 kg/m³, g = 9.81 m/s², and H the water height in metres. Each pane is treated as a rectangular flat plate simply supported on all four edges under the hydrostatic load. All arithmetic runs locally in your browser, and results are an engineering estimate — for large or public tanks have a professional review the design.
Required thickness comes from the flat-plate bending relation t = √(β · SF · P_avg · b² ÷ σ_allow), where b is the shorter pane dimension in metres, β is a plate coefficient set by the aspect ratio a/b of the longer to shorter side (β ≈ 0.287 at 1.0, 0.487 at 1.5, 0.610 at 2.0, 0.713 at 3.0, approaching 0.750 for a very long pane, interpolated between), SF is the safety factor (default 3.8), and σ_allow is the allowable bending stress — 7 MPa for annealed float glass by default, editable for other glass types. Because the load is triangular rather than uniform, the average pressure P_avg = P/2 is used, matching published aquarium glass calculators. The result is rounded up to the next standard pane: 6, 8, 10, 12, 15, or 19 mm.
As a worked example, a tank with 50 cm water height and a front pane 120 cm wide × 50 cm tall: b = 0.5 m, a = 1.2 m, a/b = 2.4 → β ≈ 0.651; P = 1000 × 9.81 × 0.5 = 4,905 Pa, P_avg = 2,452 Pa; t = √(0.651 × 3.8 × 2,452 × 0.25 ÷ 7×10⁶) ≈ 0.0147 m ≈ 14.7 mm, rounding up to a 15 mm pane. This estimate is for annealed glass only — tempered and laminated glass behave differently — and large panes benefit from eurobracing or a centre brace to limit deflection.