Postage Calculator
Weigh the letter, pick the class and destination, and get a friendly estimate of the postage — so a young letter-writer knows how many stamps to grab before the trip to the mailbox.
Postage, made simple for kids
Postage feels like a mystery until you break it into three questions: how heavy is it, what shape is it, and how far is it going? A plain one-ounce letter is the cheapest thing to send; heavier notes, square cards, and small parcels cost more, and a letter crossing a border costs more again. Working the number out together turns a chore into a little maths lesson.
Once you know the postage, use the Stamp Quantity calculator to count how many stamps to stick on, or the Mail Delivery Time estimator to guess when it will arrive.
Frequently Asked Questions
How much does it cost to mail a normal letter?
A standard one-ounce letter — a single folded sheet in an envelope — is priced at the base first-class rate, and each additional ounce adds a small charge up to the 3.5-ounce letter limit. This calculator uses those curated bands so a child can see, before licking a stamp, roughly what their letter will cost to send at home or abroad.
Why does a birthday card sometimes cost extra?
Two reasons: weight and shape. A card with a thick insert, a small keepsake, or a lot of glitter can tip past one ounce, and a square or oversized card may be charged as a large envelope rather than a letter. If your card feels heavy or stiff, choose the large-envelope class here to see the higher estimate.
Are these prices exact?
No — they are curated, rounded bands for planning and teaching, modelled on typical first-class pricing. Real postage changes with rate updates, extra services like tracking, and the exact destination country. Always confirm the live price at the post office counter or the carrier's website before you buy stamps.
How do I weigh a letter at home?
A kitchen scale works well: place the sealed envelope on it and read the ounces. As a rough guide, one folded sheet plus an envelope is about one ounce, and each extra sheet adds roughly another ounce. When in doubt, round up — a stamp too many is cheaper than a letter returned for postage.
Estimates only, using curated illustrative rate bands. Real postage changes with rate updates and extra services — confirm the live price at the counter before buying stamps.