38 Free UK Business Calculators and Tools (No Sign-Up, Nothing to Install)

The list

Nuvenar Ltd publishes 38 free tools for UK small businesses. Every tool runs in your browser. No sign-up. No email captured. No usage limits. Free forever.

The tools live at nuvenar.com/tools. This post is the pointer index - one line per tool, grouped by what you're trying to do.

WhatsApp Business API

• WhatsApp Business API Pricing Calculator - model your monthly Meta cost by conversation category
• WhatsApp Template Approval Checker - check if your template will pass Meta's approval queue
• WhatsApp Green Tick Eligibility Checker - probability score against Meta's criteria for the verified badge
• Twilio SMS vs WhatsApp Cost Calculator - per-message cost across both channels at your volume

Message and email generators

• WhatsApp Opt-in Generator (UK GDPR) - PECR-aligned consent text
• WhatsApp Welcome Message Generator - first-message templates that convert
• No-Show Recovery WhatsApp Generator - 24h and 1h confirmation flow copy
• Cold Outreach Email Sequence Generator - 4-touch B2B sequence
• Customer Win-back Email Generator - lapsed customer re-engagement

Sales, CRM and growth

• Customer Lifetime Value Calculator - CLV with retention rate and margin
• CAC Calculator - customer acquisition cost with proper attribution
• Churn Rate Calculator - monthly and annual churn
• CRM Switching Cost Calculator - data migration, retraining, integration rebuild, payback period
• Lead Response Time ROI Calculator - model conversion lift from faster reply

Bookings and hospitality

• Salon & Clinic No-Show Loss Calculator - annual revenue loss and recovery scenario
• Booking Platform Fees Calculator - real cost of Treatwell, Fresha and Booksy

UK aesthetics

• UK Aesthetics Licensing Readiness Checker - JCCP + DHSC scheme criteria
• Aesthetics Clinic ROAS Calculator - attribution across Meta + Google + walk-ins

Payments and reconciliation

• Stripe UK Fee Calculator - per-transaction cost including 3DS, chargebacks, refunds, international cards

Compliance and legal

• UK GDPR Privacy Policy Generator - ready-to-paste PECR-aligned template
• Email Deliverability Checker - SPF, DKIM, DMARC verification

Operations

• SaaS Stack Cost Audit - catalogue what you're paying across subscriptions

PDF tools (browser-side, files never leave your device)

• Merge PDF
• Compress PDF
• Split PDF
• Rotate PDF
• PDF to Word
• PDF to Excel
• PDF to JPG
• JPG to PDF
• OCR PDF - scanned document to searchable text
• Unlock PDF - remove password (you must have it)
• Watermark PDF
• Redact PDF - permanent black-out of sensitive content
• Add Page Numbers to PDF
• Edit PDF Metadata
• E-Sign PDF - draw or type signature, drop into document

Why free

Most of these calculators started as internal spreadsheets we sent to prospective NuvenarHub customers who asked things like "how much will WhatsApp Business API cost me on the volume I send?" or "is CRM switching actually worth it?".

Publishing the calculators publicly is cheaper than answering the same question forty times a month. Nuvenar Ltd is a UK company registered in England and Wales (Company No. 17240693). If the calculators lead you to trial NuvenarHub, that's a bonus. If they help you make a better decision without ever using our product, that's also fine.

No sign-up. No email. No catch.

Every tool works without an account. Every PDF operation runs in your browser (your files never touch our servers). No email is captured before you use anything. There is a paid tier (Tools Pro, £9/mo) that adds save-and-share and branded PDF export across all 38 tools, but the calculators themselves stay free forever. Hard commitment.

Related

• Full tools directory: nuvenar.com/tools
• NuvenarHub - the operating system that these tools were built alongside