Cigar Humidor Calculator (Capacity, Boveda Packs, Seasoning & Humidity)

How it works

cigar diameter = ring gauge ÷ 64 in · capacity ≈ interior in³ × 0.20 ÷ (π/4 × diameter² × length) · maker's "count" ≈ interior in³ ÷ 8.5 · two-way packs: 60 g per 25 cigars of capacity (wooden box), half for airtight, 320 g per 125 in cabinets, × 1.5 in dry rooms · seasoning: one 84% pack per 25-count for 14 days

A humidor's advertised count assumes slim cigars packed like pencils, so the honest capacity comes from the ring gauge and length actually stored, stacked in layers with room lost to dividers and the humidifier — often two-thirds of the number on the box. Humidity control is sized to the box, not to how many cigars are in it, because the cedar and the air do the absorbing, and the modern answer is two-way salt-solution packs at a chosen humidity, with more for a leaky wooden box in a dry room and fewer for an airtight container. A new cedar humidor must first be seasoned to the target humidity or it will dry the cigars for weeks, and temperature is the other guard rail, since warmth hatches beetles.

Worked example

A desktop box with a 12 × 9 × 4.5-inch interior (486 in³) would be sold as a "57-count" but holds about 41 robustos (ring 50, 5 in) once the lid humidifier, dividers and breathing room are allowed for — roughly 70% of the stated count. Keeping it at 69% in a normal room takes about 98 g of packs — two 60 g Bovedas — or 4 oz of beads, refreshed roughly every 10 weeks; a new box first needs two 84% seasoning packs for two weeks.

Frequently asked questions