Allsumhome's Takeaways:
The right medicine cabinet size is 70% to 90% of your vanity width. A 36-inch vanity needs a 25 to 32-inch cabinet. A 48-inch vanity needs a 34 to 43-inch cabinet. A 60-inch vanity needs a 42 to 54-inch cabinet — or two individual cabinets above a double-sink layout. Standard cabinet height is 30 to 36 inches, and standard depth is 4 inches for recessed installation. The complete sizing chart below covers every vanity width from 24 inches to 72 inches with exact cabinet recommendations.
Need help matching a medicine cabinet mirror to your vanity? Contact our team for free sizing advice — share your vanity dimensions and we will recommend the right series and size.
The 70-90% Rule — How to Size Any Medicine Cabinet
The most reliable sizing formula is the 70-90% rule: your medicine cabinet should be 70% to 90% of the vanity width. This range creates visual balance between the cabinet above and the countertop below.
Here is how to apply it to any vanity:
- Measure your vanity width in inches (the full countertop width, not just the sink)
- Multiply by 0.70 to get the minimum cabinet width
- Multiply by 0.90 to get the maximum cabinet width
- Choose a cabinet within that range
Example: A 48-inch vanity × 0.70 = 33.6 inches (minimum). 48 × 0.90 = 43.2 inches (maximum). So a 36-inch or 40-inch cabinet is ideal.
Going below 70% makes the cabinet look undersized and leaves awkward blank wall space on either side. Going above 90% makes the cabinet visually overpower the vanity below it. Exceeding 100% — a cabinet wider than the vanity — is not recommended under any circumstances.
If your bathroom has wall sconces on either side of the mirror, subtract 5 to 6 inches per sconce from the available wall width before applying the 70-90% rule. This ensures the cabinet does not interfere with your light fixtures. For detailed guidance on lighting clearances, see our full medicine cabinet sizing guide.
Complete Medicine Cabinet Sizing Chart by Vanity Width
This is the definitive sizing chart covering every standard vanity width. All measurements are in inches.
|
Vanity Width |
Minimum Cabinet Width (70%) |
Ideal Cabinet Width (80%) |
Maximum Cabinet Width (90%) |
Recommended Allsumhome Size |
Best For |
|
24" |
17" |
19" |
22" |
20" W single-door |
Powder rooms, compact half-baths |
|
30" |
21" |
24" |
27" |
24" W single-door |
Small full bathrooms, guest baths |
|
36" |
25" |
29" |
32" |
28" or 30" W single-door |
Standard single-sink bathrooms |
|
42" |
29" |
34" |
38" |
36" W single or double-door |
Larger single-sink layouts |
|
48" |
34" |
38" |
43" |
40" or 36" W double-door |
Single-sink with counter space |
|
54" |
38" |
43" |
49" |
48" W double-door |
Transitional single/double layouts |
|
60" |
42" |
48" |
54" |
48" W double-door OR two 24" singles |
Double-sink vanities |
|
66" |
46" |
53" |
59" |
54" or 60" W combination OR two 28" singles |
Large double-sink vanities |
|
72" |
50" |
58" |
65" |
60" or 72" W combination OR two 30" singles |
Master bathroom double vanities |
How to read this chart: Find your vanity width in the left column. Any cabinet width between the minimum (70%) and maximum (90%) columns will look proportionally correct. The "Ideal" column (80%) is the sweet spot. The "Recommended Allsumhome Size" column shows the closest standard size available in the Allsumhome lineup.
Note on combination cabinets: Cabinets wider than 48 inches are typically combination units that ship in two packages and join seamlessly during installation. Allsumhome offers combination medicine cabinets in 60" and 72" widths.
Height, Depth and Mounting Clearances
Width is the most visible dimension, but height and depth also matter for both comfort and installation.
Height
|
Cabinet Height |
Best For |
|
30" |
Standard bathrooms, most common height. Works with standard 8-foot ceilings and typical vanity light placement. |
|
32" |
Slightly taller profile for users who want more mirror surface area. Available in Boost-M1 and Boost-M2 series. |
|
36" |
Tall-format cabinets with maximum mirror coverage. Available in RIM, Illusion, and Illusion-B series. Best for bathrooms with high ceilings or no overhead light fixtures. |
The bottom edge of the cabinet should sit at least 2 to 4 inches above the faucet. The center of the cabinet should be at eye level for the primary user — typically 60 to 66 inches from the floor. If multiple household members use the same cabinet, center it at 63 inches, which works for heights from approximately 5'2" to 6'2".
Depth
Standard medicine cabinet depth is 4 inches. This is the interior shelf depth and also the minimum wall cavity depth required for recessed installation. Most interior walls built with 2x4 studs accommodate this depth comfortably.
Some models — particularly the Ample series designed for maximum storage — have slightly deeper shelves at 5 inches. Verify the spec sheet for your specific model before cutting a recessed opening.
Mounting Clearances
|
Clearance |
Measurement |
|
Above faucet to cabinet bottom |
2–4 inches minimum |
|
Cabinet center to floor |
60–66 inches (eye level) |
|
Cabinet edge to wall sconce |
5–6 inches per side |
|
Cabinet top to ceiling light |
4–6 inches minimum |
Single Cabinet vs. Double Cabinet Layouts
For vanities 54 inches and wider, you have a choice: one large cabinet or two smaller ones. Each approach has tradeoffs.
|
Layout |
Best For |
Advantage |
Tradeoff |
|
One large cabinet (48"–72") |
Single-sink vanities, visual simplicity |
Unbroken mirror surface, fewer seams, simpler install |
Combination units ship in 2 packages, heavier |
|
Two matching cabinets |
Double-sink vanities, his-and-hers storage |
Each person has dedicated storage, mirrors centered over each sink |
Small gap between cabinets, requires precise alignment |
|
One large + one small |
Asymmetric layouts, offset sinks |
Flexible placement, adapts to non-standard vanity designs |
Visually uneven — requires careful sizing to look intentional |
The standard approach for double-sink vanities: Use two identical cabinets, each sized to the 70-90% rule based on the distance from the center divider to the outer edge. For a 60-inch double vanity where each sink section is 30 inches wide, two 24-inch cabinets work well. For a 72-inch double vanity, two 28 or 30-inch cabinets are ideal.
Which Series Fits Which Vanity Size?
Each Allsumhome medicine cabinet series is available in specific width options. Here is which series works for each vanity size range:
|
Vanity Width |
Recommended Series |
Available Widths |
Key Feature |
|
24"–30" |
Boost-M1 |
20", 24", 30" |
Full LED features at the lowest price point |
|
24"–30" |
Illusion |
20", 24", 30" |
Sliding mirror doors, 10x magnifier, 1800W outlets |
|
30"–48" |
RIM |
24", 28", 30", 36", 40", 48", 56" |
Widest size range, clock/temp display, night light |
|
30"–48" |
Boost-M2 |
24", 30", 36", 40", 48" |
1800W outlet & USB, maximum functionality |
|
36"–48" |
Ample |
30", 36" |
Deepest shelves, maximum storage capacity |
|
48"–72" |
Illusion-B |
24", 30", 36", 42", 48", 54", 60", 72" |
Widest combination options, five-sided mirror, front & back LED |
|
Any |
Allsum |
16" W x 70" H |
Full-length format — floor-to-counter coverage |
If two series cover your vanity width, choose based on the features that matter most:
- Budget priority → Boost-M1
- Maximum features → Boost-M2 (1800W outlet) or Illusion (sliding doors + magnifier)
- Maximum storage → Ample
- Wide vanity / combination → Illusion-B
- Design-forward / clean lines → RIM
- Full-length mirror → Allsum
Common Sizing Mistakes to Avoid
These are the five most frequent sizing errors based on customer questions received by our installation team:
1. Choosing a cabinet wider than the vanity. A cabinet wider than 90% of the vanity width looks unbalanced and can interfere with adjacent walls, fixtures, or light sconces. Never exceed vanity width.
2. Ignoring wall sconce clearance. If you have sconces flanking the mirror location, leave 5 to 6 inches of clear wall between the sconce edge and the cabinet edge on each side. Measure the sconce-to-sconce span, not the vanity width, as your available width for the cabinet.
3. Mounting too high or too low. The center of the cabinet should be at eye level (60–66 inches from the floor), not the top of the cabinet. A common mistake is aligning the top of the cabinet with the top of a doorframe, which pushes the mirror too high for comfortable daily use.
4. Forgetting to check wall cavity depth for recessed installation. Standard cabinet depth is 4 inches, and standard 2x4 walls accommodate this. But exterior walls, walls with horizontal blocking, or walls with non-standard construction may not have the required depth. Always verify before cutting.
5. Using one oversized cabinet on a double-sink vanity instead of two. A single 60-inch cabinet above a double-sink 60-inch vanity technically fits the 100% width mark, but it means one mirror surface centered between two sinks — neither person has a mirror directly above their sink. Two 24-inch or 28-inch cabinets, one centered above each sink, is the standard recommendation.
Frequently Asked Questions
1. What size medicine cabinet do I need for a 36-inch vanity?
A 36-inch vanity needs a medicine cabinet between 25 and 32 inches wide, following the 70-90% rule. The most popular choice is a 28 or 30-inch single-door cabinet, which sits at approximately 78-83% of the vanity width. Standard height is 30 to 36 inches, and standard depth is 4 inches. Both recessed and surface mount installations work with any size in this range.
2. Should a medicine cabinet be the same width as the vanity?
No. A medicine cabinet should be narrower than the vanity — specifically 70% to 90% of the vanity width. A cabinet that matches the vanity width at 100% tends to look oversized and leaves no visual breathing room at the edges. A cabinet narrower than 70% looks undersized. The 80% mark is the ideal proportion for most bathroom layouts.
3. Is a 24-inch medicine cabinet too small for a 36-inch vanity?
A 24-inch cabinet on a 36-inch vanity is 67% of the vanity width — slightly below the recommended 70% minimum. It will function fine but may appear visually small relative to the countertop. A 28 to 32-inch cabinet brings the proportion into the 78-89% range and creates better visual balance.
4. What is the standard depth of a medicine cabinet?
The standard depth of a medicine cabinet is 4 inches. This depth accommodates most toiletries, medications, and grooming products while fitting inside a standard 2x4 wall cavity for recessed installation. Storage-focused models like the Ample series have slightly deeper shelves at approximately 5 inches, which may require additional wall cavity depth for recessed mounting.
5. Can a medicine cabinet be wider than the vanity?
No. A medicine cabinet should never be wider than the vanity it sits above. A cabinet wider than the vanity creates a visually top-heavy appearance and may extend beyond the countertop edges, which looks unintentional and unbalanced. The maximum recommended width is 90% of the vanity width.
6. What size medicine cabinet for a double vanity?
For a double-sink vanity, use two separate medicine cabinets — one centered above each sink. Size each cabinet at 70-90% of half the vanity width. For a 60-inch double vanity (30 inches per sink), use two 24-inch cabinets. For a 72-inch double vanity (36 inches per sink), use two 28 or 30-inch cabinets. This layout gives each user their own dedicated mirror and storage.
7. How high should a medicine cabinet be above the vanity?
Mount the cabinet so its center is at eye level — typically 60 to 66 inches from the floor. The bottom edge should be at least 2 to 4 inches above the faucet, and the top should be at least 4 to 6 inches below any ceiling light fixture. For households with varying heights, centering the cabinet at 63 inches from the floor accommodates most users comfortably.
The sizing chart above covers every standard vanity width from 24 to 72 inches. For vanity sizes not listed, apply the 70-90% formula to calculate your ideal cabinet width, or browse the complete medicine cabinet collection to compare all available sizes and series. If you need personalized sizing help — especially for non-standard vanity widths, double-sink layouts, or combination cabinets — get free sizing advice from our team. Free shipping on all orders to the contiguous U.S.
