I have been sending out a few big boxes. One PBS said it was over 25 pounds and I could not print my label . I took it to the post office and it was 22 pounds. The other day I printed a lable for 3 large hardcovers and it said it was 7 pounds so I printed it. When I took to the post office it was 3 pounds plus so would have been a lable for 4 pounds if PBS was calculating right. Whos responsibel for estimating weight in PBS because thay sure are messing up. 

You can never go by the estimated weight. You really have to get a postal scale and weigh it yourself or take it to the post office. I don't think anyone is "estimating" weights, that info is coming from a number of sources and databases, and is always suspect.

You are responsible for calculating the weight. If you use Paypal postage, you need to weigh your items and input the information. It is just the same if using PBS Postage. Then there will always be a difference between what the book weighs and what it weighs after adding packaging. A postal scale or food scale is the best way to calculate the weights.

i  came from the PO this morning where I tried to use the self-serve terminal cause there were 30 people in line in front of me. The scale there said the large flat envelopes would cost $1.62 each to mail.  Lucky the terminal wan't working properly and couldn't take debit/credit cards so I had to get in that long line-- actual weight at counter showed $1.32 per envelope. So even the APC scales there aren't always right.  I would have been out money if I had been able to complete check-out at the self-serve center.

Using PBS postage or any other postage service without a scale is wasteful as the weights are often incorrect. You could easily pay for a small inexpensive food or postage scale out of the money saved by not buying more postage than is necessary. I can't tell you how many books I've received that weighed under a pound, that should have cost $2.63 to mail, but the sender has bought postage several dollars above that. Want to use a postage service? Invest in a scale!

Weights on the PBS listings are sometimes right on - but more often guidelines only!  Frequently, both standard pb and mmp are released under the same ISBN - they will NOT weigh the same.  A weight showing on the listing could be either one - or even a totally different edition.  I've often found the weight for the hardcover edition on several other editions...  Digital kitchen scales are not expensive but are worth their 'weight' in gold (imo).  And yes, pun intended - :^).

I never go by the PBS estimates. Years ago I bought myself a postal scale. Best $20 I ever spent. I weigh everything before I print the postage. Sometime the estimate is off by  just off by an ounce, sometimes its off by up to a pound.

I also don't go by the PBS estimates. It's been a few years ago, but I was mailing a small paperback book and when I looked at the PBS estimate, it had it listed as 16 pounds. This was for a book that weighed less than 5 ounces.

I am taking everyones advice and buying a scale! Thanks for the input!

I get it that for some their PO is not convenient but given that PBS allows extraordinary time to mail, would it not be easier to just go there every 10 days? I just had an experience at the PO where I was sending a grandnephew a book and card. Told the PO it could not be media because of the card and first class was about $8. So I took out the card and put a stamp on it to send the other seperately. Guess what! without the card, first class was $3. No sense if a fraction of an ounce could produce this result, I want it mailed at the PO.

I love my digital scale!

Remember, too, that if you find that the weight is way off, you can correct it for the next member by submitting a data edit. Click on the title, then on "more options" --> "edit book data". Be sure to enter the book weight (not the wrapped book weight), and make any other needed adjustments to the listing. In the "reason for edit" box, mention that you have the book in hand, and have weighed it.