Calculate UK postage costs instantly. Supports 1st/2nd class, tracked services, and automatic parcel size detection.
Enter package details and click Calculate
Our Royal Mail postage calculator helps you find the cheapest way to send your package. Simply enter the weight and dimensions, and we'll automatically detect whether it's a letter, large letter, small parcel, or medium parcel.
Compare 1st class, 2nd class, Tracked 24, Tracked 48, and Special Delivery prices side by side. All rates are current for 2026.