Replacement

Replacement Mail Slot Sizing Guide: How to Measure Your Existing Mail Slot

Replacement mail slots generally come in two standard sizes: Letter and Magazine. Letter size fits standard mail and small packages, while Magazine size accommodates larger mail and catalogs without folding. The Brass-Seal Forged Brass Mail Slot System, BOTA's replacement mail slot, is available in both sizes.

How to Measure in 30 Seconds

Most replacement mail slots are designed to fit an existing opening, not require a new one. Measuring your current opening is the fastest way to determine the right size for your door.

  1. Open your existing mail slot.
  2. Measure the length of the existing opening.
  3. Measure the width of the existing opening.

Compare your measurements to the Letter and Magazine sizes below.

How to measure a mail slot opening A rectangle representing a mail slot opening, with a double headed arrow above showing the length measurement and a double headed arrow to the left showing the width, also labeled height for clarity. LENGTH WIDTH (HEIGHT) Measure edge to edge of the opening

Standard Sizes

Brass-Seal Forged Brass Mail Slot System

Size Outer L x W Opening L x W Weight
Letter (standard mail) 9.88" x 3.76" 8.00" x 2.25" 2.46 lb
Magazine (larger mail and catalogs) 13.26" x 4.01" 11.375" x 2.50" 3.16 lb

Outer dimensions are the full visible size of the hardware once installed. The opening is the actual passage through which mail travels. A standard exterior door or thicker will work with the Brass-Seal and its included screws. Door thickness affects screw length, not the mail slot opening itself. The opening never needs to be adjusted.

Seeing How It Will Mount Before You Install

A full-scale drill template lets you see exactly how the Brass-Seal will mount on your door before installing it, so you can visualize placement ahead of time rather than guessing. A precision drill template is included with every Brass-Seal system, and is also available in advance at no charge for anyone who wants to check placement before ordering. Order it here: Brass-Seal Drill Template (Free).

Choosing Interior, Exterior, or Paired

The Brass-Seal is available as an Exterior unit, an Interior unit, or both installed together as a Paired System spanning the full depth of the door.

  • Paired System: the complete solution, an Exterior and Interior unit installed together. This is the configuration most homeowners choose for a full replacement.
  • Exterior only: improves appearance and ensures proper closure of the visible exterior hardware. This is the right choice when upgrading visible exterior hardware while the interior side already has adequate hardware or an existing flap that will remain in place.
  • Interior only: often the better fit when a door's existing opening is narrower than the full Brass-Seal system requires, or when the existing flap on the interior side opens inward, and there isn't room for a second exterior style unit. It's also the right choice when preserving an existing or historic exterior mail slot, rather than replacing it.

If you're unsure which configuration fits your door, comparing your measured opening against the dimensions above is the fastest way to check before ordering.

Frequently Asked Questions

What are the two standard mail slot sizes?
Letter and Magazine. Letter size fits standard mail and small packages. Magazine size fits larger mail and small parcels without folding.

Does my door's thickness matter?
A standard exterior door or thicker will work with the Brass-Seal and its included screws. Door thickness affects screw length, not the mail slot opening itself. The opening never needs to be adjusted.

What is a drill template and do I need one?
A drill template is a full-scale guide that lets you see exactly how the Brass-Seal will mount on your door before you install it. A precision drill template is included with every Brass-Seal system, and is also available in advance at no charge if you want to check placement before ordering.

What if my existing mail slot opening doesn't match either standard size?
Compare your measured opening to the two sizes above. If it falls between sizes or you're unsure which one fits, contact BOTA for guidance before ordering.

Can I replace my mail slot without replacing my door?
Yes. Most replacement mail slots, including the Brass-Seal Forged Brass Mail Slot System, are designed to replace the existing mail slot hardware while keeping the existing door. As long as the opening is compatible with the replacement hardware, the door itself does not need to be replaced.

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