コンクリート階段計算機

コンクリートの体積、階段の寸法、スラブ厚を計算します。3D表示と材料費見積もり。

設定
mm
寸法
mm
mm
mm
mm
mm
材料・コスト
$
コンクリート体積
0
床面積
0
段数
0
蹴上げ (実寸)
0.0mm
概算費用
$0.00
Saved stair estimates stay in this browser only.
ビジュアル
Saved on this device
No data
No saved stair estimates yet.

ガイド・情報

Use this calculator for a straight concrete stair flight. It estimates the stair shape and concrete volume, but it does not replace local code checks or structural design.

使い方の説明

  1. 下の階の床から上の階の床までの「総高さ」を測ります。
  2. 希望する蹴上げ（高さ）と踏み面（奥行き）を入力します。
  3. 「スラブ厚」を設定します。これは階段の下にある構造コンクリートの厚さです。
  4. 計算機が正確な段数と必要なコンクリート量を算出します。

What the estimate includes

The tool estimates a straight stair as step triangles plus the sloped waist slab. Landings, beams, side walls, reinforcement, formwork, and waste are not included.

Step count
Total rise divided by target rise, rounded to a whole step count.
Exact rise
Total rise divided by the rounded step count.
Concrete volume
Triangular step area plus sloped waist slab area, multiplied by stair width.
Cost
Estimated concrete volume multiplied by your price per volume.

Practical examples

House stair check

Try a 2800 mm rise, 175 mm target rise, 250 mm tread, 1000 mm width, and 150 mm waist thickness to estimate a compact residential-style flight.

Compare a deeper tread

Increase the tread depth and save the calculation. The concrete volume and floor run will grow, but the stair may feel less steep.

Budget a wider stair

Change only the stair width to see how volume and cost scale for a wider flight.

Common mistakes

Measuring unfinished floors

Use finished floor levels when you know them. Floor finishes can change the real rise and make the first or last step uneven.

Treating the warning as approval

The warnings are quick checks only. Stair rules differ by country, building type, and local authority.

Forgetting landings and waste

The estimate is for the straight flight only. Add landings, edge beams, waste, and delivery minimums outside this tool.

Guessing waist thickness

Waist thickness affects volume and structure. Use the value from your drawing or ask an engineer for structural work.

Tips

Save each option

Save a few rise and run options so you can compare comfort, footprint, concrete volume, and cost.

Check the angle early

A steep angle can save space but may be uncomfortable or fail local rules. Adjust rise and run before pricing material.

Order with a margin

Concrete estimates are based on clean dimensions. Real pours often need extra for uneven ground, form losses, and ordering rules.