Sun-Mar Composting Toilets Ranked

Last updated: October 31, 2026

5 Sun-Mar composting toilets ranked. Each one is scored and ranked against every brand in its type, so "#3 mid-size" means third of all mid-size composting toilets here, not third among Sun-Mar's own.

Sun-Mar makes 5 current composting toilets: 1 urine-diverting and 4 composting. Prices run from $633 for the Sun-Mar GTG to $2,040 for the Sun-Mar Excel. Its best-rated model in each size: the Sun-Mar GTG (#4 of 19 urine-diverting, rated 3.8) and the Sun-Mar Excel NE (#1 of 6 composting, rated 3.6). 4 of 5 are NSF/ANSI 41 certified.

Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Sun-Mar composting toilets 5

  1. Sun-Mar GTG
    #4 urine-diverting3.8Full review

    Sun-Mar’s low cost urine-diverting toilet for cabins, boats and RVs, with a normal seat height and a tiny fan draw.

    Amazon $633
    $633
    -12V-
  2. Sun-Mar Excel NE
    #1 composting3.6Full review

    For off-grid cabins that need a certified toilet with no power; plan for a drain line and a tall vent.

    Sun-Mar $1,825
    $1,825
    2 peopleNone neededYes
  3. Sun-Mar Excel
    #2 composting3.1Full review

    For cabins and homes on grid power that need a certified toilet for a full time household; its power draw rules out vans and small solar systems.

    Sun-Mar $2,040
    $2,040
    3 people120VYes
  4. Sun-Mar Spacesaver
    #4 composting2.8Full review

    For a small cabin bathroom on grid power with one full time user or occasional guests, where a certified toilet is required.

    Sun-Mar $1,935
    $1,935
    1 people120VYes
  5. Sun-Mar Compact
    #6 composting2.8Full review

    For a single full time user or a weekend cabin on grid power that needs a certified toilet with a lower profile than the Excel.

    Sun-Mar $1,975
    $1,975
    1 people120VYes

Every toilet ranked