For a rectangular drop-in sink, the Kohler Archer K-2356-4-0 is 22-5/8 x 19-7/16 inches with a 16-7/8 x 12-9/16-inch bowl. For a classic oval, the American Standard Aqualyn 0476028.020 is 20-3/8 x 17-3/8 inches with a 16-inch-wide bowl. Both are white vitreous china, have an overflow and are drilled for a 4-inch centerset faucet. For a replacement, check the new sink’s template against your existing countertop opening before you buy.
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A drop-in sink rests at the countertop opening with a visible rim. The right replacement starts with the actual cutout and supported fit, then the faucet and drain.
Drop-in bathroom sinks compared
| Sink | Consider for | Faucet layout | Main check |
|---|---|---|---|
| Kohler Archer K-2356-4-0 | Rectangular; 22-5/8 x 19-7/16 in. overall; bowl 16-7/8 x 12-9/16 in., 4 in. water depth | 4-inch centerset | Actual Archer template and vanity clearance |
| American Standard Aqualyn 0476028.020 | Oval; 20-3/8 x 17-3/8 in. overall; bowl 16 in. wide, 10 in. front to back, 5-5/8 in. deep | 4-inch centerset | Supplied cutout template vs existing opening |
Both examples are vitreous china sinks with an overflow. Neither is a universal replacement for every sink with the same nominal outside size. Keep the exact model suffix with the order: a different hole layout can change which faucet works.
Kohler Archer: a rectangular option
Choose K-2356-4-0 if you want a rectangular drop-in basin and a compatible 4-inch centerset faucet. The checked white offer identified that exact model in both its model and manufacturer-part fields. Kohler’s Archer specification (resources.kohler.com) identifies an overflow, three deck holes and a required model-specific template.
Skip it if the template cannot fit the existing countertop opening, cabinet supports or backsplash clearance. A rectangular rim does not establish that the basin below it clears the cabinet. Ask for the current drawing and template before approving any countertop work.
This is a useful candidate when replacing the counter as part of a planned vanity project. For a sink-only replacement, compare the complete opening first. The shaped rim can influence how the sink looks on a narrow counter, but appearance should follow the fit check.
Check Kohler K-2356-4-0 on Amazon →
American Standard Aqualyn: an oval option
Choose 0476028.020 when you want an oval, self-rimming sink with a 4-inch centerset faucet layout. The checked offer’s title and manufacturer-part field matched this exact white model. Its shortened model field omitted leading or trailing zeros; confirm the full carton identifier on receipt.
The Aqualyn family sheet (lixil.cdn.celum.cloud) distinguishes this version from center-hole, 8-inch and extra-hole alternatives. It lists a supplied cutout template and front overflow. Do not order another Aqualyn suffix assuming the whole family has the same drilling.
Skip it if the old opening leaves too little countertop under the new rim, if the bowl hits a drawer or if you need a different faucet arrangement. Have the installer compare the actual template with the opening. An oval shape alone does not identify a replacement.
Check American Standard 0476028.020 on Amazon →
Start with the existing cutout, not the catalog width
For a replacement, collect three different sets of measurements: the sink’s outside rim, the actual countertop opening and the usable space inside the vanity. Label them clearly. A catalog listing can refer to overall size or bowl dimensions; neither is automatically the cutting line.
Record the opening’s shape as well as its maximum width and depth. Note corner curves, irregular cuts, damaged edges and the distance to the backsplash and front edge. Give the installer photographs and the old sink’s model if available. Do not remove a functioning sink solely to guess at the hidden opening.
Use the exact current template to confirm rim support and coverage around the complete opening. A larger outside dimension can still have the wrong bowl shape or mounting clearance. A rim that hides the hole from above may leave an unsupported edge underneath.
If the template does not work, have the countertop professional assess another sink or a countertop change. Do not enlarge stone, patch a structural edge or bridge an oversized opening with extra sealant as a shopping shortcut. Obtain a fit decision before the return window closes.
Choose the faucet holes as a complete system
Decide whether you are retaining the faucet before choosing the sink. Both linked examples are the specified 4-inch centerset versions. An 8-inch widespread faucet, a single-hole faucet with a suitable plate and a centerset faucet have different selection requirements.
Read the faucet maker’s permitted hole pattern, hole diameter and mounting thickness. A cover plate can conceal unused holes only when that exact faucet and plate are designed for the arrangement. It cannot make separate widespread components fit a centerset pattern.
Check working space behind and below the faucet. Handles need clearance from the backsplash, while hoses, mounting hardware and any drain linkage need room below. A faucet that fits the holes can still be inconvenient to operate or difficult to secure.
If you prefer a single-hole arrangement, compare the exact sink version with our bathroom faucet guide. Keep the approved faucet and sink documents together rather than mixing measurements from separate family listings.
Overflow, stopper and drain compatibility
These two sink examples have overflow passages. Match the drain assembly to the sink’s overflow arrangement and the faucet package. Check what is actually included; a photograph showing a faucet and stopper does not establish that either comes with the basin.
Confirm the drain opening, flange seating surface and connection below the sink with the exact drain instructions. A nominal tailpiece size does not by itself prove that a drain body fits the basin. Identify the existing trap connection and available room before planning to reuse parts.
Keep overflow openings clear during assembly. An overflow is not permission to leave a running faucet unattended, and it does not protect against every blocked drain or leak. Do not fill a questionable gap with sealant where a correctly matched component is needed.
Have the installer address corroded fittings, damaged shutoffs or misaligned piping as separate issues. A new sink should not depend on forcing the old trap into place. Our wall-hung sink guide covers a different mounting choice when a vanity replacement is being considered.
Rim seal, countertop material and installation planning
Ask the installer to confirm the sink, drain and countertop instructions together. The sealing material allowed at the sink rim can differ from the material specified at the drain. Do not assume that a product described as bathroom caulk is compatible with every countertop finish.
American Standard’s linked countertop installation instructions (lixil.cdn.celum.cloud) call for checking fit and clearance before final sealing. The maker still links this older document; obtain the current instructions supplied with the actual sink and follow the compatible countertop requirements.
Arrange access before the work starts. Empty the vanity, identify the water shutoffs and check whether a drawer, shelf or cabinet brace obstructs the new bowl or drain. Have a professional handle unreliable isolation valves and any required countertop modification.
Vitreous china needs careful handling. Inspect the delivered basin for damage before scheduling final assembly, and avoid using force to pull it into an uneven opening. If it will not sit correctly during a proper fit check, stop and resolve the cause.
A replacement checklist before you order
- Identify the existing sink. Keep its model and any original template or installation records.
- Document the opening. Distinguish actual cutout dimensions from the old rim’s outside measurements.
- Check below the counter. Include cabinet supports, drawers, faucet hardware and the trap.
- Choose the drilling. Match the exact sink suffix with the faucet’s permitted arrangement.
- Confirm the package. Record which drain, faucet, template and installation materials are separate.
- Approve the template. Have the installer confirm the actual fit before cutting or discarding the old basin.
Also check finish names on the order. White, biscuit and bone are different manufacturer selections; a screen image is not a reliable color match to an older fixture. If color is critical, compare physical references through the maker or supplier.
Accessibility also depends on the completed installation, including height, knee space and plumbing protection where required. A sink listed for an accessible application does not make every vanity arrangement compliant.
Frequently asked questions
Can I buy the same outside size as my old sink?
Outside size is only a first comparison. Confirm the exact template against the opening, rim support, cabinet and backsplash clearances.
Are all Aqualyn sinks drilled the same way?
No. The family includes different faucet-hole and overflow arrangements. Keep the exact full model and finish suffix with the order.
Will a cover plate let any faucet fit?
No. Use only a plate and hole arrangement permitted by the exact faucet instructions; check thickness and clearance too.
Does a drop-in sink include the faucet and drain?
Do not assume so. Check the exact package and drain compatibility separately, even when the listing photograph shows accessories.
Does an overflow prevent every flood?
No. It is not a substitute for supervising a running faucet, maintaining the drain or correcting a leak.
How we chose
This document-based guide makes no claim of hands-on testing. We compared maker sheets and installation text, visually checked the key specification and instruction pages, and checked standard new Amazon offers on October 14, 2026. Both offers showed stock and exact manufacturer-part identifiers. Confirm the current package and exact template with the supplier before ordering. Read our selection method and about Plumbing Picks.
Primary sources
- Kohler Archer K-2356-4 specification, June 2024 (resources.kohler.com): exact drilling, overflow and template; heading and drawing overall widths differ, so no cutting dimension adopted.
- American Standard Aqualyn 0476028.020 (americanstandard-us.com): exact white variant; do not use generic site hole-count field over the exact sheet.
- Aqualyn family specification, Rev.3 January 2020 (lixil.cdn.celum.cloud): different hole and overflow suffixes; current page still links this revision.
- American Standard countertop instructions, Rev.D (lixil.cdn.celum.cloud): fit check and clearance; exact delivered instructions control.