Your vessel's ratios, done right
Enter your vessel once and read hull speed, the key design ratios, propeller sizing and stability, using standard formulas with correct unit conversions.
One-time A$24.99 (approx. US$15) · Excel + Google Sheets · free v1.x updates · 14-day money-back guarantee, no questions asked
What’s inside
Why it beats the free calculators
- Standard formulas: fixes common metric errors
- Seven hull ratios from one vessel profile
- Comfort & capsize screening included
- Offline, editable: Excel + Google Sheets
A look inside
Questions
Why do its numbers differ from the free calculators?
The pack uses textbook formulas with correct unit conversions. Some free site calculators contain known metric errors (for example hull speed) — the pack gives the standard, correct result.
Which ratios does it cover?
Hull speed, length-to-beam, displacement-length, block coefficient, sail-area-to-displacement, the Brewer comfort ratio and the capsize screening formula — all from one vessel profile — plus propeller sizing and righting moment.
Excel or Google Sheets?
Both — a single offline file that works in Excel, Google Sheets, LibreOffice and Numbers.
Ready when you are
From the team behind the 50+ free marine calculators at boatcalculators.com.au.
14-day money-back guarantee, no questions asked