Ski DIN Calculator

A comprehensive TypeScript library for calculating ski binding DIN (Deutsches Institut für Normung) release values based on skier characteristics and skiing style.

Installation

npm install ski-din-calculator

Features

• ✅ Two calculation methods: Function-based (metric) and class-based (imperial)
• ✅ Full TypeScript support with detailed type definitions
• ✅ Input validation with descriptive error messages
• ✅ Unit conversion utilities for height and weight
• ✅ Comprehensive test coverage
• ✅ ISO 11088 compliant DIN calculation standards

Quick Start

Function-based Calculator (Metric Units)

import { calculateDIN, convertLbsToKg, convertInchesToCm } from 'ski-din-calculator';

// Calculate DIN for a skier
const result = calculateDIN(
  178,        // height in cm
  75,         // weight in kg  
  28,         // age
  2,          // skill level (1=Cautious, 2=Moderate, 3=Aggressive)
  305         // boot sole length in mm
);

console.log(`DIN Value: ${result?.dinValue}`);
console.log(`Skier Code: ${result?.skierCode}`);

// With unit conversion
const heightCm = convertInchesToCm(70);    // 177.8 cm
const weightKg = convertLbsToKg(160);      // 72.57 kg

const result2 = calculateDIN(heightCm, weightKg, 32, 3, 310);

Class-based Calculator (Imperial Units)

import { DinCalculator, SkierProfile } from 'ski-din-calculator';

const calculator = new DinCalculator();

const profile: SkierProfile = {
  height: 70,       // inches
  weight: 160,      // pounds
  age: 28,
  skill: 2,         // 1=Cautious, 2=Moderate, 3=Aggressive
  soleLength: 305   // millimeters
};

const dinValue = calculator.calculateDIN(profile);
console.log(`DIN Value: ${dinValue}`);

API Reference

Functions

calculateDIN(height, weight, age, skill, bootSoleLength)

Calculates DIN value using metric units.

Parameters:

• height (number): Height in centimeters (1-250)
• weight (number): Weight in kilograms (1-150)
• age (number): Age in years (3-100)
• skill (number): Skill level - 1 (Cautious), 2 (Moderate), 3 (Aggressive)
• bootSoleLength (number): Boot sole length in millimeters (200-360)

Returns: DINResult | null

Throws:

• InvalidHeightError: Height outside valid range
• InvalidWeightError: Weight outside valid range
• InvalidAgeError: Age outside valid range
• InvalidSkierTypeError: Invalid skill level
• InvalidBootSoleLengthError: Boot sole length outside valid range

lookupDIN(skierCode, bootSoleLength)

Direct DIN lookup by skier code.

Parameters:

• skierCode (number): Numeric skier code (1-16)
• bootSoleLength (number): Boot sole length in millimeters

Returns: DINResult | null

Utility Functions

import { 
  convertLbsToKg, 
  convertKgToLbs, 
  convertInchesToCm, 
  convertCmToInches 
} from 'ski-din-calculator';

// Weight conversions
convertLbsToKg(160);    // 72.57 kg
convertKgToLbs(75);     // 165.35 lbs

// Height conversions  
convertInchesToCm(70);  // 177.8 cm
convertCmToInches(180); // 70.87 inches

Class-based Calculator

import { DinCalculator, SkierProfile } from 'ski-din-calculator';

const calculator = new DinCalculator();
const dinValue = calculator.calculateDIN(profile);

Types

DINResult

interface DINResult {
  skierCode: string;              // Letter code (A-P)
  dinValue: number;               // Recommended DIN setting
  twistRange: [number, number];   // Acceptable twist release range
  forwardLeanRange: [number, number]; // Forward lean release range
  torqueRange: [number, number];  // Torque release range
  originalSkierCode: number;      // Numeric skier code used
  safetyWarning: string;          // Safety warnings if applicable
  suggestedRecheckInterval: string; // When to recheck DIN
}

SkierProfile

interface SkierProfile {
  height: number;      // Height in inches
  weight: number;      // Weight in pounds  
  age: number;         // Age in years
  skill: number;       // Skill level (1-3)
  soleLength: number;  // Boot sole length in mm
}

Skill Levels

• 1 - Cautious: Beginner to intermediate skiers who prefer controlled, comfortable skiing
• 2 - Moderate: Intermediate skiers who ski at moderate speeds with good control
• 3 - Aggressive: Advanced/expert skiers who ski fast and aggressively

Error Handling

The library uses specific error types for better error handling:

import { calculateDIN, InvalidHeightError, InvalidWeightError } from 'ski-din-calculator';

try {
  const result = calculateDIN(500, 75, 28, 2, 305); // Invalid height
} catch (error) {
  if (error instanceof InvalidHeightError) {
    console.log(`Height error: ${error.message}`);
    console.log(`Invalid value: ${error.value}`);
  }
}

Safety Warning

⚠️ Important: This calculator is for reference only. Always consult a qualified ski technician for final DIN settings. Incorrect DIN settings can lead to serious injury.

Contributing

Contributions are welcome! Please read our contributing guidelines and ensure all tests pass:

npm test
npm run build

License

MIT © Kris Steigerwald

This library implements the ISO 11088 standard for ski binding release calculations.