# Havanese Puppy Weight Predictor

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## Havanese Weight Predictor

    

Estimate your Havanese puppy’s adult weight from current measurements.

  

  
    Age (weeks, 8–52)
    
  

  
    Current Weight (lbs)
    
  

  
    Sex
    
      Select sex
      Male
      Female
    
  

  
    Predict Adult Weight
  

  
    

Expected Adult Weight

    

    

Typical Havanese range: 7–13 lbs. Individual results may vary.

  

  

(function () {
  function predictAdultWeight(ageWeeks, currentWeightLbs, sex) {
    var growthTable = {
      8: 0.28, 10: 0.33, 12: 0.38, 14: 0.43, 16: 0.48,
      18: 0.53, 20: 0.58, 22: 0.63, 24: 0.68, 26: 0.73,
      28: 0.77, 30: 0.81, 32: 0.84, 34: 0.87, 36: 0.89,
      38: 0.91, 40: 0.93, 42: 0.95, 44: 0.96, 46: 0.97,
      48: 0.98, 50: 0.99, 52: 1.0
    };

    var keys = Object.keys(growthTable).map(Number).sort(function (a, b) {
      return a - b;
    });

    var pct;

    if (ageWeeks = keys[keys.length - 1]) {
      pct = 1.0;
    } else {
      var lower = keys[0];
      var upper = keys[keys.length - 1];

      for (var i = 0; i < keys.length; i++) {
        if (keys[i]  ageWeeks) {
          upper = keys[i];
          break;
        }
      }

      var ratio = (ageWeeks - lower) / (upper - lower);
      pct = growthTable[lower] + ratio * (growthTable[upper] - growthTable[lower]);
    }

    var estimated = currentWeightLbs / pct;
    var sexAdj = sex === "male" ? 1.03 : 0.97;
    var mid = estimated * sexAdj;
    var low = Math.max(mid * 0.9, currentWeightLbs);
    var high = mid * 1.1;

    low = Math.round(low * 10) / 10;
    high = Math.round(high * 10) / 10;

    return [low, high];
  }

  var ageInput = document.getElementById("hwp-age");
  var weightInput = document.getElementById("hwp-weight");
  var sexInput = document.getElementById("hwp-sex");
  var button = document.getElementById("hwp-button");
  var resultBox = document.getElementById("hwp-result");
  var resultRange = document.getElementById("hwp-result-range");
  var errorBox = document.getElementById("hwp-error");

  function clearMessages() {
    resultBox.style.display = "none";
    errorBox.style.display = "none";
    errorBox.textContent = "";
  }

  ageInput.addEventListener("input", clearMessages);
  weightInput.addEventListener("input", clearMessages);
  sexInput.addEventListener("change", clearMessages);

  button.addEventListener("click", function () {
    clearMessages();

    var ageWeeks = Number(ageInput.value);
    var weight = Number(weightInput.value);
    var sex = sexInput.value;

    if (!ageWeeks || ageWeeks  52) {
      errorBox.textContent = "Please enter an age between 8 and 52 weeks.";
      errorBox.style.display = "block";
      return;
    }

    if (!weight || weight <= 0) {
      errorBox.textContent = "Please enter a valid current weight.";
      errorBox.style.display = "block";
      return;
    }

    if (!sex) {
      errorBox.textContent = "Please select sex.";
      errorBox.style.display = "block";
      return;
    }

    var result = predictAdultWeight(ageWeeks, weight, sex);
    resultRange.textContent = result[0] + " – " + result[1] + " lbs";
    resultBox.style.display = "block";
  });
})();