Stampulator - the Stamp Calculator

About stampulator

This page calculates how many 1st/2nd class stamps you need for large letters and parcels.

Read my blog about why I created this here. When Royal Mail prices change please prompt me (comment on my blog or messge me via Mastodon( and I'll update the calculations. thanks!

I was asked for a version that shows the stamps used to be below the target value. You can find that at

Royal Mail Online Pricing is sometimes different

If you're sending parcels, you might want to check Royal Mail online (also known as Click and Drop) pricing. They sometimes have discounts or offer free collections. currently links to both price lists. Example at the time of writing, the online price for a 10KG parcel is currently £6.99 and the stamp/over the counter price is £7.99

Printable page

I designed this page to be printable. It makes for a very long poster, useful for quick reference.

Which stamps do you have?

By default, it's assumed you have the standard UK 1st (£1.25p), 2nd (75p), Large 1st (£1.95p) and Large 2nd (£1.55p) which are are the October 2023 prices from Royal Mail (link also includes size and weight limits). Alternatively, enter the values of the stamps you have here and press submit. If you don't need all 4 values use a high number like 9999 so it won't be suggested in the calculation. If you'd like a page for a different country or values comment on my blog and I'll see what I can do.


Known limitations: Can only use up to 9 of each type of stamp (thus 36 stamps in total)

Your target values 125

UK Standard Services

Size Weight (up to) First Class Second Class
Letter 100g 125 75
Large Letter 100g 195 155
250g 270 240
500g 330 270
750g 330 270
Small Parcel 2kg 419 349
Medium Parcel 2kg 629 549
10kg 799 699
20kg 1199 1049

UK Signed for

Size Weight (up to) First Class Second Class
Letter 100g 275 225
Large Letter 100g 345 305
250g 420 390
500g 480 420
750g 480 420
Small Parcel 2kg 539 469
Medium Parcel 2kg 749 669
10kg 919 819
20kg 1319 1169