Ordering the wrong planner insert is one of the most common (and fixable) mistakes in the planning world. The three main 6-ring formats are A5 (148 x 210 mm / 5.83 x 8.27 in), Personal (95 x 171 mm / 3.75 x 6.75 in), and Pocket (81 x 120 mm / 3.19 x 4.72 in), and none of them are interchangeable. Each format uses a different ring spacing, so a page sized correctly but punched for the wrong system will hang crooked or simply not close.
Getting this right before you buy saves you the frustration of returns and the wait for a second shipment. This guide breaks down every size, explains the ring spacing logic behind each one, and gives you a quick measuring method so you can confirm your binder’s format in under a minute.
What are the exact dimensions of each 6-ring insert size?
The three core sizes are standardised across most brands, which makes comparison straightforward once you know the numbers.
A5 pages measure 148 x 210 mm (5.83 x 8.27 in). The six holes are punched in two groups of three, with 19 mm between each hole within a group and a 70 mm gap between the two groups. That wider centre gap is the clearest signal you are looking at a true A5 binder. A5 is the most popular 6-ring format for desk-based planning because the page is wide enough to hold a full day column alongside a notes section without feeling cramped.
Personal pages measure 95 x 171 mm (3.75 x 6.75 in). The same two-group punch pattern applies, but the centre gap narrows to 50 mm. The page itself is tall and slim, which suits appointment lists, habit trackers, and weekly spreads with a single column per day. Personal has been the dominant handbag-friendly format since Filofax introduced it in the 1930s, and the ring spacing is consistent enough that inserts from one reputable brand will almost always seat correctly in another brand’s Personal binder.
Pocket pages measure 81 x 120 mm (3.19 x 4.72 in). Unlike A5 and Personal, Pocket rings have no meaningful centre gap: all six holes are spaced 19 mm apart in a single even row. If you open a binder and the rings look evenly distributed with no visible cluster break, you are almost certainly holding a Pocket.
Personal Wide sits between Personal and A5 at 120 x 171 mm (4.75 x 6.75 in). It shares the Personal ring spacing (50 mm centre gap), so Personal Wide inserts fit any binder that takes standard Personal punching, as long as the cover is wide enough to accommodate the extra page width.
How do I measure my binder to find the right insert size?
Page dimensions matter, but the ring gap is the faster and more reliable check. Open your binder flat and locate the two middle rings, one from the top group of three and one from the bottom group of three. Measure from the centre of one to the centre of the other.
A gap of roughly 70 mm (2.75 in) means you have an A5 binder. A gap of roughly 50 mm (2 in) means Personal, Personal Wide, or FC Compact. No meaningful gap at all, with all six rings evenly spaced, means Pocket. That single measurement will tell you more than any product label will, particularly for binders bought online where “A6” is frequently used to mean Personal by some sellers.
If you have an existing insert in the binder, measuring the page itself is equally reliable. Lay it flat, measure width then height, and match against the table above. Do not measure the cover: covers extend beyond the paper on most binders, so cover dimensions are never a safe proxy for insert size.
What is the difference between Personal and Personal Wide inserts?
Personal Wide keeps the same 171 mm height and the same 6-ring punch pattern as Personal, but adds 25 mm of width, bringing the page to 120 mm across instead of 95 mm. That extra inch of horizontal space is enough to fit a two-column weekly layout or a habit tracker with checkboxes without the columns feeling squeezed.
The practical catch: a Personal Wide insert will overhang the edge of a standard Personal cover by about 25 mm. So while the holes align and the rings close, the pages will stick out past the cover. This is fine for some people and annoying for others. If you want Personal Wide inserts to sit flush, you need a binder specifically built for that format, such as those from Foxy Fix or Cloth and Paper’s Personal Wide line.
For anyone who finds standard Personal a little too narrow for daily planning but is not ready to carry an A5, Personal Wide is probably the better choice. STIL’s Personal Wide Inserts are designed with exactly this use case in mind: the extra width for layouts that breathe, without the bulk of a full A5 binder.
Does A5 fit in a half-letter binder?
No. A5 (148 x 210 mm) and half-letter (140 x 216 mm / 5.5 x 8.5 in) are close in size but use entirely different binding systems. Half-letter is almost always a disc-bound or 8-disc format, not a 6-ring format. The hole patterns are incompatible. Trying to use A5 inserts in a half-letter disc binder will result in pages that do not seat on the discs at all.
This is one of the more common mix-ups, especially for planners bought through Canadian retailers where both formats appear side by side. If the product description mentions discs, TUL, ARC, or Levenger, it is a disc-bound system and will not accept standard 6-ring punched inserts.
Ring Size Decides the Fit
The number that matters most when buying 6-ring inserts is not the page size: it is the centre ring gap. Get that measurement right and the page dimensions almost take care of themselves, because the gap is what locks you into a specific format. A5 needs 70 mm, Personal and Personal Wide need 50 mm, and Pocket needs no gap at all.
For anyone building out an A5 or Personal Wide setup in 2026, STIL’s Planner Inserts are punched to standard 6-ring spacing and designed to work across the most common binder formats. Once you know your gap, you know your size, and picking the right insert becomes a straightforward decision.
Frequently Asked Questions
Can I use A5 inserts in a Personal binder?
No. A5 inserts (148 x 210 mm) are wider and taller than Personal inserts (95 x 171 mm), and the hole spacing is different: A5 uses a 70 mm centre gap while Personal uses 50 mm. Forcing an A5 insert into a Personal binder will leave the holes misaligned and the page overhanging the cover by several centimetres.
What is the ring gap on a Personal Wide binder, and is it the same as Personal?
Yes, Personal Wide uses the same 50 mm centre ring gap as standard Personal. The only difference is page width: Personal Wide pages measure 120 mm across versus 95 mm for Personal. This means Personal Wide inserts will fit the ring mechanism of any Personal binder, but the pages will extend past a standard Personal cover unless the binder is built for the wider format.
Are STIL planner inserts compatible with Filofax binders?
STIL inserts are punched to standard 6-ring spacing. Filofax Personal binders use the standard Personal ring gap of 50 mm, and Filofax A5 binders use the standard A5 gap of 70 mm, so STIL inserts designed for those formats will seat correctly in the corresponding Filofax cover. Always confirm the format name (Personal, A5) rather than relying on general size labels.
Why do some sellers label Personal-size binders as A6?
A6 is an international paper size measuring 105 x 148 mm with a 38 mm centre ring gap. Personal measures 95 x 171 mm with a 50 mm gap. Some sellers, particularly on Amazon and AliExpress, apply the “A6” label to Personal-format binders incorrectly. If you are unsure, measure the centre ring gap: 38 mm is true A6, 50 mm is Personal.
What planner insert format works best for daily planning with a lot of detail?
A5 gives the most writing room per page in the standard 6-ring family, at 148 x 210 mm. For daily planning with time blocks, habit columns, and a notes section on the same page, A5 is the practical choice. Personal Wide at 120 x 171 mm is a reasonable middle ground if portability matters more than maximum page space.