Usage
Use the following form to calculate a sailboat standard metrics. The formulae are given at the end of this page.
The pre-loaded measurements are that of a Tanzer 7.5 - Just override them with your own values, then click the Calculate! button.
For more information on sailboat metrics, consult the Ted Brewer Yacht Design website.
The Calculator
Your Boat Measurements:
Metrics formulae explained:
All figures are based on the British Measurement Mystem.
Note: some Displacements are in British Tons (2,000 lbs), some in Long Tons (2,240 lbs).
| Metric | Formula |
|---|---|
| Sail Area - Displacement Ratio | Sail Area / (Displacement in Cubic Feet)2/3 |
| Displacement - Length Ratio | (Long Ton Displacement) / (0.01 * LWL)3 |
| Theoretical Hull Speed | 1.34 * (LWL)1/2 |
| Motion Comfort | Displacement / { 2/3 * [ (0.7 * LWL) + (1/3 * LOA) ] * Beam4/3 } |
| Balast - Displacement Ratio | (Ballast / Displacement) * 100 |
| Capsize Screening Formula | Beam / (Displacement in Cubic Feet)1/3 |
In the above formulae:
Displacement in Cubic Feet = Displacement in lbs / 64
Displacement in Long Tons = Displacement in lbs / 2,240
Calculator designed by D. Servranckx. Page updated on 2023-02-13.
********** NOTE: This page must be edited as "the Boss". ********** Update log: 2023-02-13: DS: display changes for "an". 2022-08-16: DS: minor display tweaks. 2022-01-12: DS: updated default Tanzer 7.5 data using Wikipedia data. 2022-01-11: DS: changed the Motion Confort formula TEXT to show (4/3) instead of (3/4). 2021-04-30: DS: added this section. replaced "Keel Boat" with "Keelboat".