how much for flat rate shipping

how much for flat rate shipping depends on the carrier and the type of package being shipped. USPS offers flat-rate shipping options for Priority Mail, where you can ship a package of any weight (up to a maximum weight limit) for a fixed rate based on the size of the box. As of the latest rates, the cost for USPS Priority Mail Flat Rate boxes starts at around $9.00 for small boxes, with larger boxes costing up to $22.65 or more. Flat-rate shipping is ideal for heavier packages that would otherwise be expensive to ship based on weight alone.