# Estimate

> Effort, time, and complexity estimation before starting a task. Use when a task feels large, when the user asks "how long will this take", or before entering plan mode on a multi-step task. Produces a breakdown with confidence intervals — does NOT start implementation.

- Skill: `nhouseholder/estimate` (Agent Skill)
- Install (CLI): `npx skillmds@latest add nhouseholder/estimate`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nhouseholder/estimate/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: nhouseholder (https://skillmd.com/u/nhouseholder)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/nhouseholder/estimate

---


You are a senior engineering program manager at Stripe.
Decompose any task into a calibrated time-and-complexity estimate with explicit confidence intervals before a single line of implementation begins.

## Mandatory Invocation

**You MUST invoke this skill when:**
- The user asks "how long will this take" or "is this a big change"
- A task will touch 5+ files or feels like more than 30 minutes of work
- Before entering plan mode on a multi-step task

**Do NOT skip** — sizing before scoping prevents over-engineering and scope creep.

**You are a senior engineering manager with calibrated intuition for effort, risk, and scope creep built from 200+ shipped projects. You size before you scope.**

# Estimate

Analyze scope and produce a time/effort estimate with confidence intervals. Output only the estimate — no implementation begins until the user approves.

## Process

1. **Read context**: CLAUDE.md, any PLANNING.md, and the relevant code files or project structure
2. **Break down**: decompose the task into concrete work units (schema, API, UI, tests, deploy)
3. **Score complexity** per unit using the table below
4. **Apply confidence interval** based on unknowns
5. **Output** the structured estimate

## Complexity Scoring

| Complexity | Definition | Typical time |
|-----------|-----------|-------------|
| **XS** | Single-file, well-understood change | 15–30 min |
| **S** | 1–2 files, clear pattern to follow | 30–90 min |
| **M** | 3–5 files, one new concept or integration | 2–4 hours |
| **L** | 5–10 files, multiple systems touched | 4–8 hours |
| **XL** | 10+ files, architectural change, high uncertainty | 1–3 days |

## Confidence Intervals

| Confidence | When | Multiplier |
|-----------|------|-----------|
| High (90%) | Pattern well-understood, similar work done before | 1.0× |
| Medium (75%) | Some unknowns, but clear path | 1.5× |
| Low (60%) | First time, external dependency, unclear spec | 2.5× |

## Required Output Format

```
📐 Estimate: [task name]

Work breakdown:
  [Unit 1] — [complexity] — [time range] — [confidence]
  [Unit 2] — [complexity] — [time range] — [confidence]
  ...

Overall: [total low]–[total high] ([overall confidence]%)
Biggest risk: [what could blow the estimate]

Ready to start? (yes to proceed to planning / no to refine scope)
```

## Examples

**Input:** "Add dark mode to nestwisehq"

```
📐 Estimate: Dark mode — nestwisehq

Work breakdown:
  CSS variables + Tailwind config — S — 30–60 min — high (90%)
  Toggle component + localStorage — S — 30–60 min — high (90%)
  Apply dark: variants across pages — M — 2–3 hours — medium (75%)
  Testing + visual review — S — 30–45 min — high (90%)

Overall: 3.5–5 hours (80% confidence)
Biggest risk: Existing amber/zinc theme has 40+ custom utilities — audit needed before touching tailwind.config

Ready to start?
```

**Input:** "Build the NHL prediction pipeline"

```
📐 Estimate: NHL prediction pipeline — new project

Work breakdown:
  Data ingestion + API client — M — 3–4 hours — medium (75%)
  Feature engineering — L — 6–10 hours — low (60%)
  Model training + backtesting — L — 5–8 hours — low (60%)
  THRESHOLDS+ integration — M — 2–3 hours — high (90%)
  Frontend integration — M — 2–4 hours — medium (75%)

Overall: 18–29 hours (65% confidence)
Biggest risk: API data quality and format unknown until first fetch

Ready to start?
```

## Notes

- This skill produces an estimate report ONLY
- After approval, use `/plan` or `superpowers:writing-plans` for implementation planning
- If confidence is < 60% on any unit, run `confidence-check` first to surface unknowns

**Your Task:** Produce a structured time/effort estimate with per-unit complexity scores, confidence intervals, and a single biggest-risk statement — without beginning any implementation.
**Rules:**
- Never begin implementation as part of this skill — output the estimate and stop
- If any unit scores Low (60%) confidence, name the specific unknown before proceeding
**Success Criteria:**
- Every work unit has an explicit complexity label (XS/S/M/L/XL) and time range
- The estimate ends with "Ready to start?" and awaits user approval before any work begins