IT ONLY TAKES A MINUTE!
Franking Ink Cost Calculator: Work Out Your Cost Per Frank (2026)
Ink is the running cost that most franking quotes skip over. The monthly lease gets all the attention, but cartridges can add a surprising amount over a five year term, especially if you print a big logo on every envelope.
This calculator works out what ink really costs you per frank, per month and per year, using your own cartridge price and volume.
How to use it in 3 steps
- Enter your cartridge price. Use the price your supplier charges, including VAT if you can't reclaim it.
- Enter the rated yield. This is the number of impressions the manufacturer says a cartridge produces. Your supplier can tell you.
- Enter your monthly volume and pick your impression type: plain, with a small logo, or with a large advert.
The calculator then shows your cost per frank, your monthly ink spend, your yearly spend and how many cartridges you'll need each year.
How the maths works
The basic sum is simple:
Cost per frank = cartridge price ÷ effective yield
The effective yield is the rated yield adjusted for how much artwork you print. Manufacturers usually quote yield for a standard impression. Print a large advert and you get fewer franks from each cartridge.
The calculator uses these adjustments:
| Impression type | Yield used |
|---|---|
| Plain impression (postage and date only) | 100% of rated yield |
| With a small logo or return address | 85% of rated yield |
| With a large advert or slogan | 70% of rated yield |
These are planning assumptions, not manufacturer figures. Real yield varies by machine, cartridge and design. If your supplier gives you a yield for your exact impression, enter that and choose plain.
Monthly ink cost = cost per frank × monthly volume
Cartridges per year = (monthly volume × 12) ÷ effective yield, rounded up.
Worked example
Here's how it works with example inputs. These are not real prices for any machine. Use your own quote.
| Input | Example value |
|---|---|
| Cartridge price | £60 |
| Rated yield | 4,000 impressions |
| Impression type | Small logo (85%) |
| Monthly volume | 1,000 items |
Effective yield = 4,000 × 0.85 = 3,400 franks.
Cost per frank = £60 ÷ 3,400 = about 1.8p.
Monthly ink cost = 1.8p × 1,000 = about £17.65.
Cartridges per year = 12,000 ÷ 3,400 = 3.5, so 4 cartridges.
Yearly ink cost = about £212 at the per frank rate, or £240 if you buy whole cartridges.
Why ink cost matters
Compare that 1.8p per frank with the postage saving. From 7 April 2026, a 1st Class letter is £1.77 franked against £1.80 stamped, a saving of 3p. A 2nd Class letter is 88p franked against 91p stamped, also 3p (Royal Mail Business Price Guide).
So on standard letters, ink can eat more than half of your per item saving. On large letters, where the saving is 44p for 1st Class up to 100g, ink is a much smaller share. That's why franking pays off most for businesses that send plenty of large letters.
How to cut your ink cost
- Simplify your advert. A smaller logo uses less ink.
- Turn off the advert for bulk runs. Some machines let you switch it off for certain batches.
- Ask about larger cartridges. Some models have high yield options with a lower cost per frank.
- Check what's included. Some leases include a set number of cartridges each year.
- Don't buy too far ahead. Ink has a shelf life, so order what you'll use.
Our franking ink prices guide and ink cartridges page have more detail.
Genuine vs compatible
Compatible cartridges can be cheaper, but many leases say you must use genuine ink. For Mailmark machines, print quality matters because the barcode has to be readable by Royal Mail. Check your contract before switching.
Calculator spec
For transparency, here are the rules the calculator follows:
- Inputs: cartridge price (£), rated yield (impressions), monthly volume (items), impression type (plain, small logo, large advert).
- Yield factors: plain 1.00, small logo 0.85, large advert 0.70.
- Outputs: cost per frank (pence, 1 decimal place), monthly cost (£, 2 decimal places), yearly cost (£), cartridges per year (rounded up).
- Default values: £60, 4,000, 1,000 items, small logo.
FAQs
How long does a franking ink cartridge last?
It depends on the yield and your volume. A 4,000 impression cartridge lasts about four months at 1,000 items a month.
Does a logo really use more ink?
Yes. More printed area means more ink per impression.
Should ink be included in my lease?
It's worth asking. Some suppliers include ink, which makes budgeting easier.
Compare running costs
Ask each supplier for cartridge price and yield, then run both through the calculator. Our cost calculator covers the full cost of ownership. Compare franking machine prices.
