Three configurations most projects start from
If you're not sure where your staircase fits, these three cover the most common layouts before you branch into a more specific configuration below.
Spiral Staircase Calculator
Tread rotation, center pole diameter, and headroom for a full spiral stair.
L-Shaped Staircase Calculator
90Β° turn layout, with a toggle for a landing or winder treads at the turn.
Deck Stair Calculator
Outdoor stringer layout that accounts for ground slope and open risers.
Browse by configuration
Grouped into three practical sets β turning staircases, tight-access ladders, and outdoor or landscape steps.
Turns & Configurations 7
Spiral Staircase Calculator
Tread rotation, center pole diameter, and headroom for a full spiral stair.
Winder Staircase Calculator
Pie-shaped winder tread geometry for any staircase that turns without a landing.
L-Shaped Staircase Calculator
90Β° turn layout, with a toggle for a landing or winder treads at the turn.
U-Shaped Staircase Calculator
180Β° turn layout, with a toggle for a landing or winder treads at the turn.
Curved Staircase Calculator
Freeform curved stringer geometry and radius-based tread sizing.
Floating Staircase Calculator
Cantilevered tread spacing, support depth, and open-riser sightlines.
Switchback Staircase Calculator
Multi-flight parallel layout for tall commercial or industrial vertical rises.
Access & Utility 3
Alternating Tread / Ship Ladder Calculator
Steep-space stair layout for utility rooms and loft access.
Attic / Loft Ladder Calculator
Folding or fixed ladder sizing for attic and loft access.
Basement Stair Calculator
Layout for confined-height basement stairwells.
Outdoor & Landscape 5
Deck Stair Calculator
Outdoor stringer layout that accounts for ground slope and open risers.
Exterior / Outdoor Stair Calculator
Weather-adjusted rise and run for uncovered outdoor stairs.
Porch Step Calculator
Short-run entry step sizing from porch to grade.
Garden / Landscape Step Calculator
Sloped-ground step and landing spacing for garden paths.
Pool Step Calculator
Submerged step depth and tread sizing for pool entries.
Common questions about stair types
What's the difference between L-Shaped and U-Shaped calculators?
Which calculator handles a staircase that turns without a landing?
I'm building attic access, not a full staircase β which tool do I need?
Do these calculators check code compliance too?
Browse the other 9 categories
Once your configuration is set, these are the natural next stops β structural sizing, material take-offs, railing, code checks and cost.