Founder / finance lead

Unit economics calculator

Immediate result: CAC, LTV, LTV:CAC, payback period and contribution margin, with each formula shown.

Problem it solvesTeams quote CAC and LTV without agreeing on the formulas, so the numbers mean nothing.

Download SKILL.md
Add this skill to
ChatGPTClaudeGeminiPerplexity

You paste

Spend ₹6 lakh/month · 300 new customers · ARPU ₹800/month · margin 70% · churn 5%/month

You get

CAC = 6,00,000 ÷ 300 = ₹2,000

LTV = 800 × 0.70 ÷ 0.05 = ₹11,200 · LTV:CAC = 5.6

Payback = 2,000 ÷ (800 × 0.70) = 3.6 months

About this skill

About Unit economics calculator

Teams quote CAC and LTV without agreeing the formulas, so the numbers don't mean much. This skill calculates customer acquisition cost, lifetime value, the LTV to CAC ratio, payback period and contribution margin from your inputs, showing every formula and stating the period of each input. It explains what the results say about the business, shows how they move if churn or CAC changes by 20% and lists the caveats. Founders use it before fundraising; finance teams use it to settle definitions. To use it, paste the skill into your assistant and send marketing and sales spend, new customers, average revenue per customer, gross margin and churn; the reply opens with “Metrics table with formulas”.

Unit economics calculator AI skill for Founder / finance lead: you paste "Spend ₹6 lakh/month · 300 new customers · ARPU ₹800/month · margin 70% · churn 5%/month" and get "CAC = 6,00,000 ÷ 300 = ₹2,000"
Unit economics calculator — example input and the first lines it returns. Works in ChatGPT, Claude and Gemini.
Job profile
Finance & accounting · Founder / finance lead
Works in
ChatGPT, Claude, Gemini, Copilot, Claude Code
Format
Agent Skills (SKILL.md)
Price
Free, no sign-up
Install instructions

Copy, paste, send

  1. Cold email writerCopy skillCopied ✓1 Copy the skillPress Copy skill.
  2. ANY AI ASSISTANTSKILLPaste here, then press Enter2 Paste it into a new chatChatGPT, Claude, Gemini or Copilot.
  3. ANY AI ASSISTANT3 Send your inputSend marketing and sales spend.
The skill — paste this into your AI assistant
# Skill: Unit economics calculator

You are running the "Unit economics calculator" skill for me. I work as: Founder / finance lead. What I need from you: CAC, LTV, LTV:CAC, payback period and contribution margin, with each formula shown.

## When I send you marketing and sales spend, new customers, average revenue per customer, gross margin and churn
1. Compute CAC = acquisition spend ÷ new customers.
2. Compute LTV = ARPU × gross margin ÷ churn rate.
3. Compute LTV:CAC and CAC payback in months.
4. Explain what the numbers say and which lever matters most.

## Reply in this format
- Metrics table with formulas
- Interpretation
- Sensitivity: what if churn or CAC changes 20%
- Caveats

## Rules
- State the period of every input (monthly vs annual).
- Use only the facts I give you; mark anything you had to assume with [ASSUMPTION].
- If something essential is missing, ask me one short question, then continue.
- No preamble or filler: start with the result.

Confirm you're ready in one line, then wait for me to send marketing and sales spend, new customers, average revenue per customer, gross margin and churn.

Then sendMarketing and sales spend, new customers, average revenue per customer, gross margin and churn. For example: Spend ₹6 lakh/month · 300 new customers · ARPU ₹800/month · margin 70% · churn 5%/month

ChatGPT

  1. Fastest: paste the skill as your first message in a new chat, then send your input.
  2. To keep it: open a Project, choose Instructions (or Settings → Personalization → Custom instructions for every chat) and paste it there.
  3. To share it with a team: create a custom GPT and paste the skill into its Instructions.
  4. In the Codex app: copy the skill's folder into ~/.codex/skills/ (or Customize → Skills → Add → Create skill).

Claude

  1. Fastest: paste the skill as your first message in a new chat, then send your input.
  2. To keep it: create a Project, open Project instructions and paste the skill.
  3. As a Claude Skill: download the skill's ZIP, then in Claude open Settings → Skills → Add → Upload skill and choose the file.

Gemini

  1. Fastest: paste the skill as your first message in a new chat, then send your input.
  2. To keep it: open Gems → New Gem, paste the skill into Instructions and save.

Microsoft Copilot

  1. Fastest: paste the skill as your first message, then send your input.
  2. In Microsoft 365 Copilot, save it as a prompt or paste it into an agent's instructions to reuse it.

Any other assistant

  1. Paste the skill as the system prompt or first message in any chat assistant (Perplexity, Meta AI, DeepSeek, Mistral, local models).
  2. Coding agents that read the Agent Skills format (SKILL.md) can load the downloaded file from their skills folder.

Install it permanently

Upload it to Claude, add it to ChatGPT's Codex app, clone it into Claude Code, or download the SKILL.md for any agent. Full guide with screenshots →

Download the ZIP and upload it in Claude. Claude then uses the skill on its own whenever a request matches.

Download ZIP

Quick setup

  1. In Claude, open Settings → Skills (under Customize).
  2. Click Add → Upload skill.
  3. Choose the ZIP — don't unzip it — and make sure the skill is switched on.
Claude Settings with Skills selected under Customize, and the Add menu open showing Upload skill, Create a skill, Create with Claude and Record your screen

Repositoryscienceofapps.com/skills/ai-skills.git · all 200 skills, one folder each, plain git over HTTPS

What it does

The steps it follows

  1. Compute CAC = acquisition spend ÷ new customers.
  2. Compute LTV = ARPU × gross margin ÷ churn rate.
  3. Compute LTV:CAC and CAC payback in months.
  4. Explain what the numbers say and which lever matters most.
What you get back

The reply format

  • Metrics table with formulas
  • Interpretation
  • Sensitivity: what if churn or CAC changes 20%
  • Caveats

Rules it never breaks

  • State the period of every input (monthly vs annual).
  • Uses only the facts you give it and marks assumptions.
FAQs

Questions about Unit economics calculator

What does the Unit economics calculator skill do?

Teams quote CAC and LTV without agreeing on the formulas, so the numbers mean nothing. The skill fixes that: cAC, LTV, LTV:CAC, payback period and contribution margin, with each formula shown.

How do I install Unit economics calculator in ChatGPT, Claude or Gemini?

Copy the skill and paste it as the first message of a new chat, then send your input. To keep it, paste it into a ChatGPT Project or custom GPT, a Claude Project or a Gemini Gem, or upload the SKILL.md file as a Claude Skill.

What do I send Unit economics calculator after installing it?

Send marketing and sales spend, new customers, average revenue per customer, gross margin and churn. If something essential is missing, the skill asks you one short question and then continues.

Is the Unit economics calculator skill free?

Yes. It's free to copy, use and adapt, with no sign-up, and works in the free versions of ChatGPT, Claude, Gemini and Copilot.

More for finance & accounting
Finance operations

Expense claim checker

ProblemExpense claims break policy in small ways that slip through manual review.

You paste

Policy: meals ₹1,500/day, receipts over ₹500 · claims: dinner ₹2,100, taxi ₹650 no receipt

You get

Dinner ₹2,100 — over the ₹1,500 daily limit (clause 3.1) → approve ₹1,500

Taxi ₹650 — receipt missing (clause 2.4) → hold

Approvable now: ₹1,500 of ₹2,750

Immediate resultEach claim checked against your policy, with violations, missing receipts and the amount to approve.

How to use it
Founder / non-finance manager

Financial statement explainer

ProblemP&Ls and balance sheets are hard to read for anyone outside finance.

You paste

Revenue ₹4.2 crore, COGS ₹2.9 crore, opex ₹1.6 crore, current assets ₹1.1 crore, current liabilities ₹1.4 crore

You get

The business lost ₹30 lakh: gross profit ₹1.3 crore didn't cover ₹1.6 crore of operating costs.

Gross margin = 1.3 ÷ 4.2 = 31% · current ratio = 1.1 ÷ 1.4 = 0.79

Watch: a current ratio below 1 means short-term bills exceed short-term assets.

Immediate resultA plain-English explanation of your statements with key ratios and three things to watch.

How to use it
CFO / founder

Board finance summary

ProblemBoard decks bury the financial story in tables.

You paste

Q3: revenue ₹3.1 crore (plan ₹3.4), burn ₹45 lakh/month, cash ₹6.3 crore

You get

Headline: Revenue 9% behind plan; runway 14 months at current burn.

Runway = ₹6.3 crore ÷ ₹45 lakh = 14 months

Ask: approve the hiring freeze on non-revenue roles until Q4 revenue lands.

Immediate resultA one-slide financial summary: headline, five numbers, what changed and what you need.

How to use it

All 12 finance & accounting skillsAll 200 skillsRead it in the articleProve it: Financial Statement Analysis Certification (free test)

Free PDF · 74 pages · 2 editions

The Laws of UX, in one field guide

60 research-backed principles in 6 categories — what each one means, why it works on the human brain and how to use it on your own screens. Written by Sushant Singh, founder of Science of Apps, who has scaled consumer apps to lacs of users and spent 10+ years leading product across startups and digital businesses in the US, EU & India.

Pick your edition
Free. No card, no paywall — just your email.
Free PDF · 74 pages

Get Laws of UX by email

Choose your edition

You’ll also get occasional UX psychology tips. Unsubscribe anytime. Privacy policy

Free PDF · 90 pages · 2 editions

100+ Subscription Paywalls, decoded

110 real paywalls from top apps, taken apart, rated out of 5 and decoded with the Laws of UX — plus the frameworks, copy and checklists to ship your own. By Sushant Singh, founder of Science of Apps.

  • 110 paywalls rated
  • 34 Laws of UX
  • 12 frameworks

Which paywall scored 4.8 out of 5, and which scored 2.6? It’s all inside.

Pick your edition
Free. No card, no paywall — just your email.
Free PDF · 90 pages

Get 100+ Paywalls, Decoded by email

Choose your edition

You’ll also get occasional UX psychology tips. Unsubscribe anytime. Privacy policy