Growth Math — B2B SaaS Marketing Calculators by GO — ALex

GROWTH MATH — FIVE MARKETING CALCULATORS FOR B2B SaaS

Growth Math is a free toolkit of five marketing calculators built for
B2B SaaS founders, growth leaders, and CRO/RevOps teams. Open the popup,
type your real numbers, get a structured answer — no sign-up, no email
gate, no telemetry, no ads. Every calculation runs entirely in your
browser; nothing is uploaded or stored anywhere outside your machine.

Built by Global One Digital, a B2B SEO and automation agency working with
Series A through Series C SaaS companies in the US and EU. We extracted
these five calculators from the spreadsheets our team kept rebuilding
across client engagements — packaging them into a browser extension made
the work reusable and gave clients a tool they could check anytime.

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1. SEO ROI CALCULATOR
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Project monthly organic traffic, leads, closed deals, revenue, break-even
month, and 12-month ROI from your B2B SEO investment. Useful before
signing an agency retainer or building an internal SEO program.

What you enter:
• Number of commercial keywords you target
• Average monthly searches per keyword
• Target SERP position (1-20)
• Visitor-to-lead conversion rate (%)
• Lead-to-deal conversion rate (%)
• Average deal size ($)
• Monthly SEO investment ($)

Under the hood:
• Advanced Web Ranking 2024 study CTR data per position
(pos 1 ≈ 32% CTR, pos 3 ≈ 10%, pos 5 ≈ 6%, pos 10 ≈ 2%)
• Realistic 12-month ramp curve: month 1 delivers 5% of steady state,
rising to 65% by month 6 and 100% by month 12. This is the
differentiator most "SEO ROI" calculators skip — they assume month-1
results equal steady state, which over-promises by 15-20× early.

What you get:
Monthly organic visits, leads, closed deals, revenue
Break-even month (when cumulative revenue ≥ cumulative spend)
12-month ROI as a percentage

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2. AUTOMATION SAVINGS CALCULATOR
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Calculate the financial case for automating a recurring workflow. Useful
before scoping an n8n, Make, Zapier, or custom-code build.

What you enter:
• Tasks per week
• Minutes per task
• Hourly rate of the person doing the task ($)
• Manual error rate (%)
• Average cost per error ($)
• One-time automation build cost ($)

Under the hood:
• Conservative 95% labor automation (rarely 100%, full elimination
is uncommon)
• Conservative 92% error reduction (good automation systems still
have edge cases)
• Three-year horizon for net savings calculation

What you get:
Hours freed per month
Monthly labor savings ($)
Monthly error-cost savings ($)
Total monthly savings ($)
Payback period in months
3-year net savings ($)

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3. CAC + LTV CALCULATOR
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Diagnose unit economics health: customer acquisition cost, lifetime
value, ratio, payback months, and a letter grade (A through D) based
on standard SaaS health benchmarks.

What you enter:
• Monthly marketing + sales spend ($)
• New customers per month
• Average MRR per customer ($)
• Gross margin (%)
• Monthly churn rate (%)

Under the hood:
• Average customer lifetime = 1 / monthly churn
• LTV = MRR × gross margin × lifetime in months
• LTV:CAC grading: A (≥ 5), B (3-5), C (1.5-3), D (< 1.5)

What you get:
CAC ($), LTV ($), LTV:CAC ratio
CAC payback in months
Letter grade with color-coded indicator

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4. A/B TEST SAMPLE SIZE CALCULATOR
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Calculate the visitors-per-variant you need before starting an A/B test,
plus days/weeks to reach statistical significance at your daily traffic.

What you enter:
• Baseline conversion rate (%)
• Minimum detectable effect (% relative)
• Confidence level (90 / 95 / 99)
• Statistical power (80 / 85 / 90)
• Daily visitors per variant

Under the hood:
• Standard two-proportion z-test sample size formula
• Same math used by Optimizely, VWO, Convert, and Google Optimize
• z_α and z_β values pre-computed for standard confidence/power pairs

What you get:
Sample size per variant
Total sample size (both variants)
Days and weeks to reach significance at current traffic

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5. SaaS PRICING → ARR FORECAST CALCULATOR
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Project ARR at 12 and 36 months from your tiered pricing mix and customer
acquisition rate. Useful for pricing strategy and board-deck forecasting.

What you enter:
• Starter / Growth / Enterprise tier prices ($/month)
• Customer mix percentage across tiers
• New customers per month
• Monthly churn rate (%)

Under the hood:
• Month-by-month MRR simulation with exponential retention
(mrr = mrr × (1 - churn) + new_mrr_per_month)
• Mix percentages auto-normalise if they don't sum to 100
• ARPU = weighted average of tier prices

What you get:
ARPU
MRR after 12 months
ARR after 12 months
ARR after 36 months

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INSIDE THE POPUP
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▸ 5 calculator tabs + 3 information tabs (How to Use / Glossary / About)
▸ Copy Result button on every calculator — sends a clean text summary
to your clipboard, perfect for pasting into Slack or a doc
▸ EN/RU language switcher in the top-right (preference saved locally)
▸ A built-in Glossary explaining every metric used in the calculators
(CTR, MRR, CAC, LTV, MDE, churn, ramp curve, statistical power, etc.)
▸ Quick-start How-to-Use guide with per-calculator tips

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PRIVACY & TECHNICAL TRANSPARENCY
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No data leaves your browser. No analytics. No telemetry. No tracking
pixels. No third-party requests at runtime. We do not collect, store,
or transmit any input data.

The only thing we save locally (via chrome.storage.local) is your
language preference — one string, either "en" or "ru". Inputs are not
saved; close the popup, the numbers are gone. This is intentional —
we do not want sensitive revenue figures persisted anywhere.

The extension ships as approximately 200 lines of readable JavaScript
plus HTML and CSS. No minification, no obfuscation. Open
chrome://extensions, enable developer mode, click the Growth Math card,
and inspect every file. The math formulas are commented inline.

Permissions requested:
• storage — only for saving your EN/RU language preference

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WHO THIS IS FOR
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✓ B2B SaaS founders at Series A through Series C
✓ Growth and marketing leaders evaluating SEO or automation investments
✓ CRO and RevOps teams running A/B tests
✓ Pricing strategists modeling tier mix and ARR forecasts
✓ Agency professionals who need quick sanity checks during client calls

Not for:
✗ Consumer-grade B2C marketing (calculators assume B2B economics)
✗ E-commerce with $20 average order value (deal sizes assume B2B SaaS)
✗ Pre-product-market-fit startups (numbers will be too speculative)

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LANGUAGES
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English (primary) and Russian — auto-detected from browser locale and
switchable inside the popup. Result number formatting also follows the
selected locale (US comma vs RU space as thousands separator).

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ABOUT GLOBAL ONE DIGITAL
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We are a B2B SEO and automation agency for Series A through Series C
SaaS companies in the US and EU. Our service line covers:

• B2B SaaS SEO — technical audits, keyword strategy by funnel stage,
content production tied to commercial intent, link building through
digital PR, pipeline-tied reporting
• Workflow automation — n8n self-hosted, Make.com, Zapier, custom code
for the long tail
• LLM integration — production-grade RAG, evaluations, observability
on top of OpenAI, Claude, and Gemini APIs
• Headless and Jamstack development — Next.js, Astro, Strapi,
Contentful, Sanity, Storyblok

Learn more or book a discovery call:
https://development-web.com/
https://development-web.com/seo/
https://development-web.com/business-process-automation/
https://development-web.com/n8n-consulting/
https://development-web.com/llm-integration/
https://development-web.com/contacts/

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FEEDBACK & ROADMAP
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Next versions planned:
• Sales velocity calculator
(deal size × opportunities × win rate / sales cycle)
• Content production budget planner
• Public-data keyword volume estimator (Wordstat-style)

Have a calculator you keep rebuilding in spreadsheets that fits this
B2B SaaS toolkit theme? Reach out via https://development-web.com/contacts/
— that's exactly how this extension started.