Compound Miter Angle For a 5 Sided Planter 20 Degree Slope
Miter 34.32° / Bevel 11.6°
- 5 sides
- Slope from vertical: 20°
Methodderived from the panel face-normal geometry of a regular 5-sided frustum — see /tools/angle-calculator/ for the full derivation.
Slope is measured from the HORIZONTAL here (0° = flat frame) — some published tables measure tilt from the vertical instead, which gives the same physical cut with different-looking numbers. Confirm which axis your saw calls which before cutting a test piece.
A 5-sided planter with sides sloped 20° needs a 34.32° miter and an 11.6° bevel — the steepest slope and the largest bevel of any planter combination on this site, because a pentagon flared this aggressively looks less like a garden planter and more like a flared urn or vase form.
Why this one specifically
Five-sided planters are unusual to begin with — the flat pentagon miter (36°) already trips people up because it isn't a round, guessable number, and adding a steep 20° flare on top compounds that unfamiliarity with the largest bevel angle in the whole planter set. That combination is exactly why this shape gets built less often as a straightforward garden box: at 20° of outward lean, the five panels widen dramatically from base to rim, which suits a decorative urn or a plant stand meant to be looked at more than a working raised bed meant to hold a lot of soil.
What moves the number
One convention note before cutting: an unflared, straight-sided pentagon reads as 0° on this site, with the figure climbing as the panels flare out from there — plenty of published compound-angle references count the same lean from vertical instead, so a chart that disagrees isn't necessarily wrong, just built on a different starting line. A shallower slope on the same 5-sided base would pull the bevel back down substantially; check the tool for other combinations.