OceanCalc

VMG Calculator — Examples

Updated recently with improved calculation accuracy and expanded examples.

Velocity made good toward a mark: boat speed × cos(angle off bow to the mark).

Last updated: April 22, 2026

Author: OceanCalc Editorial Team · Publisher: Albor Digital LLC

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Explore typical numbers with the VMG Calculator. Try the examples in the Examples section below while you vary inputs in the calculator.

VMG Calculator

Result

VMG (kn)

4.6

Formula

VMG = BSP × cos(θ), θ from bow toward mark

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Use this calculation together with proper navigation tools to improve route accuracy and on-water decision making.

What is the VMG Calculator?

Velocity made good toward a mark: boat speed × cos(angle off bow to the mark).

0° = dead ahead; 90° = VMG 0 toward mark along heading (pure beam reach to mark geometry).

VMG

Velocity made good (VMG) is the component of the boat’s speed toward or away from a mark or waypoint, critical for upwind and downwind tactics.

Overview

Velocity made good (VMG) is the component of the boat’s speed toward or away from a mark or waypoint, critical for upwind and downwind tactics. A VMG Calculator is used in maritime navigation to perform precise calculations based on established nautical formulas. This tool allows you to apply your inputs to the stated nautical relationships using accurate and standardized methods.

Key takeaways

  • VMG CalculatorVelocity made good (VMG) is the component of the boat’s speed toward or away from a mark or waypoint, critical for upwind and downwind tactics.
  • FormulaVMG is the component of velocity toward a waypoint along your heading-to-mark geometry.
  • How to useType your figures into the form; outputs refresh so you can compare cases quickly.

Recommended Marine Navigation Tools

These tools are commonly used alongside navigation calculations for real-world sailing and route planning.

These are optional tools used by sailors and marine professionals. Choose based on your navigation setup.

How to use

Type your figures into the form; outputs refresh so you can compare cases quickly.

Formula

Core relationship: VMG = BSP × cos(θ), θ from bow toward mark

VMG is the component of velocity toward a waypoint along your heading-to-mark geometry.

0° = dead ahead; 90° = VMG 0 toward mark along heading (pure beam reach to mark geometry).

Practical use cases

VMG Calculator: passage planning, crew briefings, instrument-to-chart unit checks, and verifying mental math when tired or in rough weather.

Tips for accuracy

  • Match input units to your chart, GPS, or instrument before trusting the VMG Calculator.
  • Cross-check important outputs with a second method or crew when visibility or motion is poor.
  • Treat simplified models (waves, radar horizon, etc.) as estimates; real conditions vary.

Practical examples

  • 6 kn at 30° → ~5.2 kn VMG

Frequently Asked Questions

  • How accurate is this calculator?

    It uses standard maritime formulas and noted approximations. Use it for planning and checks; confirm safety-critical decisions with official sources.

  • Can I use this on mobile?

    Yes. Layouts are responsive for phones and tablets on deck or in the cockpit.

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When to Use This Calculation

  • • Planning a navigation route between two points
  • • Adjusting course based on wind, current, or drift
  • • Verifying distances and bearings during passage planning
  • • Supporting manual navigation alongside GPS systems

Popular calculators: Nautical Mile Converter · Knots to km/h Converter · Hull Speed Calculator · Initial Bearing Calculator · Great Circle Distance Calculator · Boat Fuel Consumption Calculator · VMG Calculator

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These calculations are based on standard maritime navigation formulas used in seamanship, chart navigation, and marine route planning.

Results are estimates for educational purposes only and should not be used for real navigation decisions.

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OceanCalc is a precision-focused maritime calculation platform built for sailors, navigators, and marine professionals. All formulas are derived from established navigation principles including great-circle computation, rhumb line navigation, and classical seamanship mathematics.

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