Growth Math — B2B SaaS Marketing Calculators by GO

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 ═══════════════════════════════════════════════

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

═══════════════════════════════════════════════ 2. AUTOMATION SAVINGS CALCULATOR ═══════════════════════════════════════════════

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 ($) Payback period in months 3-year net savings ($)

═══════════════════════════════════════════════ 3. CAC + LTV CALCULATOR ═══════════════════════════════════════════════

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

═══════════════════════════════════════════════ 4. A/B TEST SAMPLE SIZE CALCULATOR ═══════════════════════════════════════════════

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

═══════════════════════════════════════════════ 5. SaaS PRICING → ARR FORECAST CALCULATOR ═══════════════════════════════════════════════

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

═══════════════════════════════════════════════ INSIDE THE POPUP ═══════════════════════════════════════════════

▸ 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

═══════════════════════════════════════════════ PRIVACY & TECHNICAL TRANSPARENCY ═══════════════════════════════════════════════

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

═══════════════════════════════════════════════ WHO THIS IS FOR ═══════════════════════════════════════════════

✓ 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)

═══════════════════════════════════════════════ LANGUAGES ═══════════════════════════════════════════════

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).

═══════════════════════════════════════════════ ABOUT GLOBAL ONE DIGITAL ═══════════════════════════════════════════════

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/

═══════════════════════════════════════════════ FEEDBACK & ROADMAP ═══════════════════════════════════════════════

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.