A macerating toilet uses a small electric motor inside a holding tank behind or below the bowl to grind waste into a slurry, then pump that slurry uphill — through a 3/4" or 1" PVC line — to wherever you can tie into an existing soil stack. It's the workaround that lets you add a basement bathroom, garage bathroom, or pool-house bathroom without breaking the concrete slab. The category was effectively created by Saniflo (France, 1958) and they still own ~70% of US sales.

How a macerator actually works

A standard toilet flushes into a 3" or 4" drain line that runs downhill by gravity to a sewer or septic. A macerator replaces that with a sealed plastic box behind the bowl containing a grinder blade and a small pump. When you flush, water and waste enter the box; the grinder activates for 5–10 seconds; the pump fires; everything moves through a 3/4" or 1" pressurized line that can travel up to 15 feet vertically or 150 feet horizontally (less if you combine vertical+horizontal). The line ties into an existing drain or vent — typically into a sanitary tee in your soil stack on the floor above.

When this is the right answer

Basement bathroom retrofits — adding below the slab without ejector-pit excavation. The #1 use case.
Garage / accessory-structure conversions — converting a detached garage to a guest suite with a half-bath.
Behind a tile floor that can't be cut — adding a half-bath against a finished concrete or terrazzo floor.
Boats and tiny houses — sub-floor space for plumbing is at a premium.
Pool houses and outbuildings — too far from the main soil stack for gravity drain runs.

When it's the wrong answer

You're already running new plumbing in a remodel — use a gravity drain.
You can't supply electricity to the unit (it's a 110V/15A appliance).
Cottage / vacation property used 2 weeks a year — the macerator unit will sit dry, seals degrade, you'll have a pump failure on first reuse.
Hard-water area without a softener — calcium scales on the impeller cause early failure.

The Saniflo line, decoded

Sanicompact — $1,100. Combination toilet+macerator in one molded unit. The compact option for a powder room.
Saniaccess 2 — $1,200. Macerator pump only (the bowl is sold separately or paired with any standard 1.6 GPF tank toilet). Removable cover for service access — a real improvement over earlier sealed designs.
Saniaccess 3 — $1,400. Same as Saniaccess 2 but with two additional inlet ports for connecting a sink and shower to the same pump. The full bathroom solution.
Sanibest Pro — $1,800. Heavy-duty grinder for commercial settings; handles wet wipes (sometimes), heavier paper loads, longer pump runs. The "pro" upgrade for guest-house and small-business installs.
Sanigrind — $1,500. Grinder-only model — works behind any existing toilet that you want to keep, adding macerating capability to an existing fixture.

What you'll actually pay (installed)

Saniflo unit: $1,100–$1,800
Discharge line: $50–$200 in PVC + check valves + insulation if running cold areas
Electric tie-in: $150–$300 (the unit needs a dedicated 110V GFCI circuit)
Plumber labor: $400–$900
Turnkey: $1,800–$3,300 for a basement bathroom that would have otherwise required $8,000+ of slab break-and-pour for a gravity drain

Operating reality (the day-to-day)

The pump runs for 8–15 seconds after each flush. Audible — about 60 dB — louder than a standard flush.
Don't flush wipes (even "flushable" ones — the grinder gets tangled), feminine hygiene products, or anything other than human waste and toilet paper. This is the #1 cause of warranty failure.
The pump needs an annual descaling in hard-water areas — pour vinegar or Saniflo's cleaning solution through the system every 12 months.
Service life: 10–15 years for the unit. Replacement is straightforward (remove old, install new, same connections) and DIY-feasible.