HelpMeSendIt — Postage Tools (Stamp Mixer)

Mix the stamps you already have (1st/2nd, Large, top‑ups) to meet or slightly exceed today’s Royal Mail prices. Letters, Large Letters, Small/Medium Parcels, and International Standard. Signed For supported.

  • Lowest overpay, fewest stamps, conserve NVIs
  • Printable letter/large-letter gauge
  • UK & International letters; parcels too
  • No affiliation with Royal Mail

What it does

Enter your item’s size and weight, pick 1st/2nd (and Signed For if needed), then tell us which stamps you have. We suggest the best stamp combinations that meet today’s price.

Real NVI values
Counts 1st/2nd/Large at today’s rates
Stamp top‑ups
Use 1p/2p/5p… to make up
Formats
Letter, Large Letter, Small/Medium Parcel
International
Europe & World zones

Royal Mail Stamp Mixer

Enter your item and the stamps you have. We’ll suggest combinations that meet or slightly exceed today’s postage price. Supports UK Letters/Large Letters, Small/Medium Parcels (Standard or Signed For), and International Standard Letters/Large Letters.

Prices last updated: Aug 11, 2025
Region
Class

1) Your item

FormatLetter
Weight bandUp to 100g
Price (1st)£1.70

Size limits per Royal Mail. Parcels are classified by max length × width × depth after rotating the item. Tracked 24/48 require barcoded labels (not payable with stamps). International goods usually need a customs form.

2) Your stamps

1st Class (NVI)
Value £1.70
2nd Class (NVI)
Value £0.87
1st Large (NVI)
Value £3.15
2nd Large (NVI)
Value £1.55
1p
Value £0.01
2p
Value £0.02
5p
Value £0.05
10p
Value £0.10
20p
Value £0.20
50p
Value £0.50
£1
Value £1.00
£2
Value £2.00

NVIs count at today’s rates. Top up with make-up values as needed. Old non-barcoded regular stamps aren’t valid.

3) Suggested mixes

Fewest stamps
Required
£1.70
Suggested
£1.70
Overpay
£0.00
Stamps
1
  • 1st Class (NVI)× 1
Conserve NVIs
Required
£1.70
Suggested
£2.00
Overpay
£0.30
Stamps
1
  • £2× 1

Notes

  • Any combination that meets or exceeds the price is accepted. Overpaying is okay; underpay risks a surcharge.
  • Signed For items must be posted at a Post Office counter. Tracked 24/48 labels are bought online or at the counter and don’t use stamps.
  • International: documents can go without customs forms; goods/gifts usually need a CN22/CN23.
Prices are guidance only. Always check Royal Mail’s latest price list. Last updated: Aug 11, 2025.

How it works

  1. We classify your item as Letter / Large Letter / Parcel using Royal Mail size & weight limits.
  2. We look up today’s price (including Signed For if selected).
  3. You enter the stamps you’ve got — 1st/2nd (NVIs) and make‑up values.
  4. We find stamp mixes that reach or slightly exceed the price, minimising overpay and stamp count.

FAQs

Can I mix 1st and 2nd Class stamps?

Yes. Non‑value indicator (NVI) stamps count at today’s value; top up with make‑up stamps as needed.

What are the Large Letter size limits?

Up to 353×250×25 mm and 750 g.

Are old non‑barcoded stamps valid?

No. Use barcoded stamps (or swap old ones via Royal Mail’s swap‑out scheme).

Do I need the Post Office for Signed For?

Yes, Signed For items must be handed over at a Post Office counter.

Can I use stamps for Tracked 24/48?

Tracked services require a barcoded label (bought online or at the counter), not stamps.