The Maker Bench · Craft Tool

Wax Seal Bead & Melting Calculator

Never guess spoon wax amounts or ruin an envelope with overflowing edges. Calculate precise bead counts, weight, melting duration, and postal guidelines for 20mm, 25mm, 30mm, and custom stamp heads.

25 mm
Single envelope
Required Spoon Load
3–4 beads
Recommended for a single 25mm stamp
Estimated Total Weight:0.9 grams
Optimal Melting Time:60–80 seconds
Pouring Tip: Pour when texture resembles warm honey. If tiny bubbles appear, lift spoon away from the flame for 10 seconds to cool slightly.
Mailing Caution: Inside envelope recommended. If mailing externally on USPS, apply the 44¢ Non-Machinable Surcharge stamp so postal sorters do not shear off the wax.

Stamp Size & Bead Reference Table

Stamp DiameterClean RimClassic LipPlump OverflowBest For
20 mm (Mini)2 beads2–3 beads3 beadsGift tags, place cards, RSVP cards
25 mm (Standard)2–3 beads3–4 beads4–5 beadsEnvelope flaps, wedding stationery
30 mm (Large)4 beads5 beads5–6 beadsMonogram crests, ribbon wrapping, gift boxes

Frequently Asked Questions

How many wax beads do I need for a 25mm stamp?

For a standard 25mm (1-inch) brass stamp head, use 3 to 4 octagonal beads. 3 beads create a tidy, clean edge; 4 beads produce a full, organic, raised rim that looks luxurious.

Why does my wax seal have tiny air bubbles?

Air bubbles mean the wax overheated in the spoon. Lift your melting spoon 1 to 2 inches higher above the tea light flame, and stir gently with a toothpick or stirring rod. The wax should flow like thick honey, not water.

Can I mail letters with wax seals through USPS?

Yes, but letters with wax seals on the outside envelope are classified as 'non-machinable' because sorting rollers can crack the seal or jam the sorting machine. You must add the USPS Non-Machinable Surcharge (or hand-cancel at the counter), or place the sealed envelope inside a larger protective outer envelope.

How do I calculate wax for 50 or 100 wedding invitations?

Multiply your beads-per-seal by the invitation count and add 10% for test pours. For 100 invitations using a 25mm stamp (at 3.5 beads average), you need about 385 beads, which is approximately 115 grams (or 2 standard 60g bags).

Need a complete wax sealing walkthrough?

Read our curated field guide on temperature control, stamp releasing techniques, and tested sealing kits.

Explore the Wax Seal Kits Field Guide →