Here are the latest rates straight from stamps.com

Postcard $0.33 $0.32 $0.33 $0.32
Post Office/Retail Rates Stamps.com Rates
Flat Rate Envelopes 2013 Postage Rates 2012 Postage Rates 2013 Postage Rates 2012 Postage Rates
Priority Mail Express Flat Rate Envelope $19.95 $18.95 $18.11 $17.75
Priority Mail Express Padded Flat Rate Envelope $19.95 $18.95 $18.11 $17.75
Priority Mail Express Legal Flat Rate Envelope $19.95 $18.95 $18.11 $17.75
Priority Mail Flat Rate Envelope $5.60 $5.15 $5.05 $4.90
Priority Mail Padded Flat Rate Envelope $5.95 $5.30 $5.70 $5.10
Priority Mail Flat Rate Legal Envelope $5.75 $5.30 $5.25 $5.10
Post Office/Retail Rates Stamps.com Rates
Packages 2013 Postage Rates 2012 Postage Rates 2013 Postage Rates 2012 Postage Rates
Priority Mail Express (0.5 lb.) $14.10 and up $12.95 and up $13.09 and up $12.85 and up
Priority Mail Express Flat Rate Box $39.95 $39.95 $39.95 $39.95
Priority Mail (1 lb.) $5.60 and up $5.20 and up $5.05 and up $4.90 and up
Priority Mail Small Flat Rate Box $5.80 $5.35 $5.15 $5.15
Priority Mail Medium Flat Rate Box $12.35 $11.35 $11.30 $10.85
Priority Mail Large Flat Rate Box $16.85 $15.45 $15.30 $14.65
Priority Mail APO/FPO/DPO Large Flat Rate Box $14.85 $13.45 $13.30 $12.65
Priority Mail Regional Rate Box A $6.07 and up $5.79 and up $5.32 and up $5.04 and up
Priority Mail Regional Rate Box B $6.91 and up $6.65 and up $6.16 and up $5.90 and up
Priority Mail Regional Rate Box C $15.86 and up $15.19 and up $15.11 and up $14.44 and up
First Class Mail Package Service (1 oz.) $2.07 $1.95 $1.69 $1.64
Parcel Select (1 lb.) Not Available Not Available $5.42 $5.20
Media Mail (1 lb.) $2.53 $2.47 $2.53 $2.47
Standard Post (formerly Parcel Post – 1 lb.) $5.60 $5.20 Not Available $5.20
Library Mail (1 lb.) $2.40 $2.35 $2.40 $2.35
Post Office/Retail Rates Stamps.com Rates
International 2013 Postage Rates 2012 Postage Rates 2013 Postage Rates 2012 Postage Rates
Global Express Guaranteed (0.5 lb.) $49.95 and up $44.00 and up $47.45 and up $44.00 and up
Priority Mail Express Intl (0.5 lb.) $33.95 and up $29.25 and up $32.59 and up $26.91 and up
Priority Mail Express Intl Flat Rate Box –Canada $64.95 $59.95 $64.95 $59.95
Priority Mail Express Intl Flat Rate Box – Other Countries $79.95 $74.95 $79.95 $74.95
Priority Mail Express Intl Flat Rate Envelopes – Canada $34.95 $29.25 $34.95 $29.25
Priority Mail Express Intl Flat Rate Envelopes – Other Countries $44.95 $38.00 $44.95 $38.00
Priority Mail Intl (1 lb.) $28.25 and up $23.25 and up $27.40 and up $22.09 and up
Priority Mail Intl Flat Rate Envelopes – Canada $19.95 $12.95 $19.95 $12.95
Priority Mail Intl Flat Rate Envelopes – Other Countries $23.95 $16.95 $23.95 $16.95
Priority Mail Intl Small Flat Rate Box – Canada $19.95 $12.95 $19.95 $12.95
Priority Mail Intl Small Flat Rate Box – Other Countries $23.95 $16.95 $23.95 $16.95
Priority Mail Intl Medium Flat Rate Box – Canada $40.95 $32.95 $40.95 $32.95
Priority Mail Intl Medium Flat Rate Box – Other Countries $59.95 $47.95 $59.95 $47.95
Priority Mail Intl Large Flat Rate Box – Canada $53.95 $39.95 $53.95 $39.95
Priority Mail Intl Large Flat Rate Box – Other Countries $77.95 $60.95 $77.95 $60.95
First Class Package Intl Service – Canada (1 lb.) $10.55 $5.75 $9.50 $5.75
First Class Package Intl Service – Mexico (1 lb.) $15.05 $9.29 $13.55 $9.29
First Class Package Intl Service – Asia, Europe, Australia (1 lb.) $16.75 $11.60 $15.08 $11.60
First Class Package Intl Service – Other Countries (1 lb.) $16.25 $11.26 $14.63 $11.26
First Class Mail Intl Letters – Mexico & Canada (1 oz.) $1.10 $0.85 $1.10 $0.85
First Class Mail Intl Letters – Other Countries (1 oz.) $1.10 $1.05 $1.10 $1.05
Post Office/Retail Rates Stamps.com Rates
Special Services 2013 Postage Rates 2012 Postage Rates 2013 Postage Rates 2012 Postage Rates
Certified Mail $3.10 $2.95 $3.10 $2.95
Certificate of Mailing $1.20 $1.15 $1.20 $1.15
Registered Mail $11.20 and up $10.95 and up $11.20 and up $10.95 and up
USPS Tracking $0.90 $0.75 and up $0.20 $0.19
Restricted Delivery $4.75 $4.55 $4.75 $4.55
Return Receipt – (mail) $2.55 $2.35 $2.55 $2.35
Return Receipt – (electronic) $1.25 $1.15 $1.25 $1.15
Return Receipt – (for Merchandise) $4.10 $3.95 $4.10 $3.95
Signature Confirmation $2.70 $2.55 $2.20 $2.10
Adult Signature – (Basic) Must be purchased online Must be purchased online $4.95 $4.75
Adult Signature – (Person Specific) Must be purchased online Must be purchased online $5.15 $4.95