A coin collection is small but dense — a box near 12 × 10 × 6 inches that can hit 6–20 lb from the metal. Actual weight drives the modest price; the real considerations are security and keeping graded slabs from cracking. Postage itself varies by lane and speed, so weigh the packed box and run your true ZIPs rather than assuming a figure.
Behind this guide sits one real quote: a 10 × 8 × 2 in box at 5.5 lb, priced $12.53 by USPS Ground Advantage on the lane described below.
On 2026-07-24 the SMKlog calculator was handed “Album of 50 collectible silver coins in flips” and a route running Manchester, NH 03101 to Boise, ID 83702. Its full response appears below, exactly as generated: box, weight, and rates all inferred from the description, with nothing weighed or measured by hand.
Album of 50 collectible silver coins in flips
The count and the flips are the useful details. A bare “coins” would drop the estimate onto a generic category average; fifty silver pieces in an album implies a specific, dense little package.
10 × 8 × 2 in
25 × 20 × 6 cm
Packed weight 5.5 lb (2.5 kg).
Manchester, NH 03101
to Boise, ID 83702
New Hampshire to Idaho, priced live on two real ZIPs. Nothing else about this small box influences the total the way that mileage does; a two-state hop would cost noticeably less.
Coins bill by the scale, full stop: this box's dimensional equivalent is a mere 1.2 lb (10 × 8 × 2 ÷ 139) against 5.5 lb of metal, so actual weight sets every rate below. Only a comically oversized carton could make size matter here.
| Carrier | Service | Price | Estimated transit |
|---|---|---|---|
| USPS | Ground Advantage | $12.53 | 5-6 business days |
| UPS | Ground Saver | $13.53 | 7 business days |
| UPS | Ground | $16.23 | 8-9 business days |
| USPS | Priority | $16.73 | 4-5 business days |
The prices are all-in checkout amounts, with the label and SMKlog's charge already combined and no later billing. USPS Ground Advantage came out ahead on this run at $12.53. Carriers adjust tariffs often enough that this table is best read as a July 2026 snapshot; for a collection you're actually mailing, get the current figure on your own ZIPs.
About 12 × 10 × 6 in once boxed. Keep coins in their flips, tubes, or graded slabs and immobilize them so they can't shift against each other. Use a plain, unmarked outer box and a strong double-wall carton for the concentrated weight.
6–20 lb packed. The rate uses whichever is greater, real weight or the dimensional figure; for coins that's nearly always the scale, which is exactly why the box should stay as small as the collection allows.
Zone and speed do almost all the work on a dense little box like this. The Manchester to Boise example crosses the country, yet the spread stayed narrow: $12.53 to $16.73 across four services. Closer destinations compress that further; expedited air stretches it. Since every lane lands differently, the calculator prices yours instead of quoting an average.
Plan around 12 × 10 × 6 in packed. Keep coins in their flips, tubes, or graded slabs and immobilize them so they can't shift against each other. Use a plain, unmarked outer box and a strong double-wall carton for the concentrated weight.
Typically 6–20 lb packed. Carriers charge on the larger of two figures, the scale reading or length × width × height divided by their divisor, so the finished box needs weighing before you quote. A dense coin box guessed light is a guaranteed post-shipment adjustment.
Use a plain box with no hint of the contents, add tracking with signature on delivery, and buy declared-value protection for the appraised amount. Immobilize graded slabs so the holders can't crack.
Coins are dense metal, so even a small box can hit 15–20 lb. Use a double-wall carton because the concentrated weight will tear out of a thin box corner if it's dropped.
Actual weight rules here. Coins are dense: a 12x10x6 in box runs about 12 lb, and at that size dimensional pricing never comes into play — carriers bill the real scale weight. That leaves two drivers: the zone between ZIP codes and how fast you want it there, with ground the sensible default. The SMKlog calculator prices your collection's actual weight and route across USPS, UPS, and FedEx at once.
Dense boxes reward flat-rate pricing. Compare USPS Priority Mail flat-rate boxes — one price regardless of weight, which favors 12 lb of metal in a small box — against USPS Ground Advantage and UPS or FedEx ground priced by weight and zone. Short zones often tip toward weight-based pricing; long hauls favor flat rate. Whichever wins, buying the label online at commercial rates typically beats counter prices by 20-40%.