What is cd-calculator?

A set of seven Python command-line calculators for architecture, engineering, and construction work. They cover geometry, structures, sunlight, panels, meshes, materials, and fabrication costs.

Use it to analyze geometry and meshes, check structures, calculate solar values, optimize panels, estimate materials, and estimate fabrication costs.

It replaces repeated hand calculations with consistent results that can be checked or passed into design tools.

cd-calculator — Skill for Claude Code by Abhinavbwj

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add Abhinavbwj/Claude-skills-for-Computational-Designers --skill cd-calculator

Clone the repo

git clone --depth 1 https://github.com/Abhinavbwj/Claude-skills-for-Computational-Designers

Made for: Claude Code.

Or install Claude-skills-for-Computational-Designers, the plugin that ships this one along with the rest of its 18 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator/github.svg)](https://agentmods.dev/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator)

Your own site

<a href="https://agentmods.dev/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator"><img src="https://agentmods.dev/badge/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator"><img src="https://agentmods.dev/badge/skills/abhinavbwj/claude-skills-for-computational-designers/cd-calculator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 5,800 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00030	$0.05800
Opus 5	$0.00015	$0.02900
Sonnet 5	$0.00006	$0.01160
Haiku 4.5	$0.00003	$0.00580

Measured 12d ago against content hash 7361e868b7b7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

cd-calculator scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

The scan reads SKILL.md. This mod also ships 7 executable files (scripts/fabrication_calculator.py, scripts/geometry_calculator.py, scripts/material_estimator.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

result = subprocess.run(

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

cd-calculator — 100% identical, 0 lines differ

skills/cd-calculator/SKILL.md · 635 lines

How it starts

The opening of the file, as written. The whole thing — 635 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Computational Design Calculator

Calculator Overview

This skill provides 7 production-grade Python calculators purpose-built for computational design workflows in Architecture, Engineering, and Construction (AEC). Each calculator is a standalone command-line tool that accepts domain-specific parameters and returns precise, well-formatted results.

All calculators share common design principles:

Human-readable output by default with clear section headers, formatted tables, and summary statistics.
--json flag on every calculator for structured machine-readable output, enabling pipeline integration with parametric design tools, Grasshopper scripts, Dynamo graphs, or custom automation.
Strict input validation with meaningful error messages that guide the user toward correct usage.
SI units throughout (millimeters for geometry, kilonewtons for forces, degrees for angles) with Imperial equivalents noted where relevant.
Deterministic calculations based on published engineering formulas (Eurocode, ASCE, ASHRAE) so results can be cross-checked and audited.

Calculator Index

#	Calculator	Script	Primary Domain
1	Geometry Calculator	`geometry_calculator.py`	Cross-section properties
2	Structural Checker	`structural_checker.py`	Member sizing & verification
3	Solar Calculator	`solar_calculator.py`	Solar position & radiation
4	Panel Optimizer	`panel_optimizer.py`	Facade rationalization
5	Mesh Analyzer	`mesh_analyzer.py`	Mesh quality & topology
6	Material Estimator	`material_estimator.py`	Quantity takeoff & carbon
7	Fabrication Calculator	`fabrication_calculator.py`	CNC / 3D print / laser costing

Directory Structure

cd-calculator/
  SKILL.md                          # This file
  references/
    formulas.md                     # Complete formula reference
  scripts/
    geometry_calculator.py          # Cross-section geometry
    structural_checker.py           # Beam/column/deflection checks
    solar_calculator.py             # Solar position & radiation
    panel_optimizer.py              # Panel clustering & waste
    mesh_analyzer.py                # OBJ mesh quality analysis
    material_estimator.py           # Material quantity takeoff
    fabrication_calculator.py       # Fabrication time & cost

Read the full file on GitHub · 635 lines

Files

What ships with it

8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

12d ago First seen · 635 lines · 30 tokens per session scan A 7361e868b7b7

Subscribe to this mod's changes

cd-calculator is a skill published in the GitHub repository Abhinavbwj/Claude-skills-for-Computational-Designers (212 stars, last pushed 5mo ago), licensed MIT. It adds 30 tokens to every session and 5,800 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Scientific calculator computation fabrication geometry materials mesh panels solar structural

cd-calculator