How Much Ink Is in a Fountain Pen Cartridge & Converter?

There are many different fountain pen ink cartridges and converters, all with slightly different ink capacities. I've compared each type below so you don't have to.

The average ink cartridge will hold 0.7 to 1.2ml of ink, with short cartridges of 0.7ml being the most common. The average converter will hold between 0.6ml and 1ml of ink, with 0.8ml being the most common. The average piston filler fountain pen holds 1.2 to 2.5ml of ink. The average eyedropper pen holds around 2.5ml of ink.

I can get a lot more specific than those ranges, so I will be listing every cartridge and converter I could find or measure myself, including some pens.

In this article:

1. Comparison of Cartridge & Converter Ink Capacity
2. Ink Capacity of Fountain Pens
3. How Long Can You Write with a Fountain Pen?

Comparison of Cartridge & Converter Ink Capacity

Below you'll find a comparison of the ink capacity of differently-sized cartridges and converters. As you'll see, converters hold less ink than cartridges. All are within the same capacity range.

Cartridge ink capacity

• Short international cartridge: 0.7ml
• Long international cartridge: 1.45ml
• Lamy T10 cartridge: 1.15ml
• Parker long Quink cartridge: 1.4ml

Converter ink capacity

• Lamy Z27 converter: 0.8ml
• Lamy Z28 converter: 0.8ml
• Pilot Con-20: 0.9ml
• Pilot Con-40: 0.61ml
• Pilot Con-50: 0.6ml
• Pilot Con-70: 1-1.1ml
• Montblanc converter: 0.5ml
• Graf von Faber-Castell Converter: 0.9ml
• Parker standard converter: 0.6ml
• Parker long squeeze converter: 0.9ml
• Parker short squeeze converter: 0.5ml
• Pilot Custom 74 (Con-70): 1.1ml
• Pilot Metropolitan converter: 0.9ml

What is surprising about this comparison, is that most regular converters hold less ink than short international cartridges. This is even more the case for long international cartridges, as well as Lamy's and Parker's long cartridges: those hold substantially more ink than most converters. This is to be expected, since the converters use filling mechanisms while having the same available space in the pen body. Typically, converters hold substantially less ink compared to their similarly-sized ink cartridges.

If you want to know how long each cartridge will last you, I've researched that as well. You can learn exactly how many pages you can write with different nibs here (jumps to section in article on cartridge economy).

Below, I'll discuss some of the cartridges and converters in more detail, and we'll touch on the ink capacity of different fountain pens too. Spoiler: most fountain pens hold way more ink than when using a cartridge, but you'll still be surprised at the massive amount of ink some of them can hold.

More detailed discussion on ink capacity

An international short cartridge holds approximately 0.7ml of ink, which will allow you to write roughly 45 pages with a fine nib, 18 pages with a medium nib, and 14 pages with a broad nib.

International ink cartridges contain either 0.7ml of ink (short) or 1.45ml of ink (long). Their dimensions are 38mm long or 73mm long respectively. They are both 7mm in diameter.

A standard Parker cartridge can hold up to 1.4ml of ink, but since these cartridges aren't filled completely, they contain 1.18ml of ink instead. 0.15ml of that is in the emergency reservoir. This amount will allow you to write roughly 76 pages with a fine nib, 30 pages with a medium nib, or 24 pages with a broad nib.

There are different Parker pen refills available, but all have the same opening size. The most popular is the standard long cartridge, which is 75mm long and 7mm in diameter and includes an 0.15ml emergency reservoir supplementing the main reservoir of 1.3ml. Parker also makes short Quink cartridges, which hold around 0.8ml of ink and is 38mm long and 7mm in diameter.

A standard Montblanc converter holds 0.5ml of ink, making it one of the lowest capacity converters available, with the next smallest being the Pilot Con-50 with a capacity of 0.6ml.

Ink Capacity of Fountain Pens

Below is a selection of piston-filler and eyedropper fountain pens taken from my detailed comparison of the ink capacity of fountain pens for comparison with the cartridge and converter capacities above. As you can see, the ink capacity of fountain pens that don't use cartridges or converters is typically higher, as we would expect.

Piston-filler fountain pens

• Pelikan M800: 1.2ml
• TWSBI Eco piston: 2.5ml
• Lamy 2000: 2.67ml
• Pilot Custom 823: 1.3ml
• Montblanc 146: 1.4ml
• Montblanc 149: 2.1ml

Eyedropper fountain pens

• Moonman C1: 4ml
• Moonman M2: 2.5ml
• Noodler's Charlie Pen: 2.5ml
• Opus 88: 2ml

All these numbers are good and well, but how long can I write with them? Let's explore that exact question now.

How Long Can You Write with a Fountain Pen?

I've looked into how long you can write with a fountain pen comparing three different nibs (fine, medium, broad) to get an idea of how exactly how many pages each type of cartridge or converter will get you. The results were quite surprising. Typically, a full standard cartridge will write 14-45 pages, depending on nib size. Long cartridges will write roughly 29 to 93 pages.

However, it all depends on the nib size, paper, and ink type. If you want to learn more, you can read my research on how long a 50ml of ink will last. Here, I'll calculate ink consumption and how long you can use each converter before needing to refill.