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Weight Calculator: what your piece weighs and how it mails
Choose a paper stock and the finished dimensions and the calculator returns the weight per piece and the USPS mail-class tiers it qualifies for. The arithmetic is the one our estimators use, on the same stock list.
Use it to plan postage before you commit to a stock.
Quick Reference
- Letter weight limit: 3.5 oz. Above that, the piece must mail at flat or parcel rates.
- Flat weight limit (Marketing Mail): 16 oz (1 lb). Above that, parcel rates apply.
- First-Class flat limit: 13 oz.
- Bound Printed Matter: up to 15 lb (240 oz) for book-like and catalog content.
- GSM (grams per square meter) is the universal paper-weight measure. US "basis weight" varies by paper type; the stock list above shows both.
Weight moves the rate and the drop-ship plan. Once you know it, the Mail Date Planner turns a drop date into a schedule.
Planning a mailing?
Send us the piece and the quantity. Postage is usually the largest line on a mailing, and it is decided before anything prints. We will tell you what your piece actually qualifies for.