StairCalc3D Guides

Staircase guides: history, calculation & safety

Short, practical guides about spiral staircases — how to calculate risers and treads, choose materials, stay safe and meet building codes. Every article includes a live calculator you can try below.

10 in-depth guides 5 languages 100% free calculator

All guides

How to Calculate a Spiral Staircase, Step by Step Calculation

How to Calculate a Spiral Staircase, Step by Step

Calculate the number of steps, riser height, diameter, tread and opening of a spiral staircase. A complete beginner-friendly guide with the formulas the calculator uses.

2 min read →
Blondel’s Rule: the Formula for Comfortable Stair Steps (2R + G) Calculation

Blondel’s Rule: the Formula for Comfortable Stair Steps (2R + G)

For two centuries the Blondel rule has told builders whether a stair is comfortable. Learn the 2R + G formula and how to apply it to spiral staircases.

2 min read →
Spiral Staircase Safety: Handrails, Headroom and Slip-Resistant Treads Safety

Spiral Staircase Safety: Handrails, Headroom and Slip-Resistant Treads

Is a spiral staircase safe? Learn the essentials: handrails on both sides, minimum headroom, even risers, non-slip treads and the codes that keep people safe.

2 min read →
Compact Spiral Staircases for Small Spaces, Lofts and Mezzanines Design

Compact Spiral Staircases for Small Spaces, Lofts and Mezzanines

Loft, mezzanine or tiny home? Learn the minimum sizes, step rules and design tricks to fit a safe spiral staircase into a small footprint.

2 min read →
Stair Materials Compared: Steel, Wood, Concrete and Glass Materials

Stair Materials Compared: Steel, Wood, Concrete and Glass

Steel, wood, concrete or glass — which stair material is right for you? Compare cost, durability, maintenance, noise and looks for spiral staircases.

2 min read →
Spiral vs Straight Staircase: Which One Should You Choose? Design

Spiral vs Straight Staircase: Which One Should You Choose?

Straight stairs are simple and wide; spiral stairs save space and add drama. Compare cost, comfort, safety and footprint to pick the right staircase for your project.

2 min read →
Who Invented the Spiral Staircase? From Castles to Palaces History

Who Invented the Spiral Staircase? From Castles to Palaces

The spiral staircase is a medieval engineering classic. Learn who invented it, why castle towers used clockwise stairs, and how it became a symbol of palace elegance.

1 min read →
When Were Stairs Invented? The Ancient Origins of the Staircase History

When Were Stairs Invented? The Ancient Origins of the Staircase

Stairs are one of humanity’s oldest inventions. Discover where the first stone steps were carved, how ancient builders solved them, and why their geometry still shapes spiral staircases today.

1 min read →
Why Spiral? Shells, Snails and the Golden Ratio Behind Spiral Stairs Geometry

Why Spiral? Shells, Snails and the Golden Ratio Behind Spiral Stairs

Nature loves the spiral — snail shells, sunflowers and galaxies all grow in curves. Discover the geometry (and the golden ratio) that makes a spiral so strong and space-efficient.

2 min read →
Staircase Design Tips: Proportions, Light, Storage and Flow Design

Staircase Design Tips: Proportions, Light, Storage and Flow

A great staircase is about more than steps. Learn practical design tips — proportions, natural light, storage under the stair and traffic flow — before you buy or build.

2 min read →