JavaScript Source Code 2002: Calculators: Pregnancy Calculator

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Pregnancy Calculator

Enter the mother's pregnancy information into this calculator and JavaScript will provide an estimated conception date, birth due date, and an estimated current fetal age. Great for all those mothers-to-be!

JavaScript Source Code 2002: Calculators: Pregnancy Calculator
Simply click inside the window below, use your cursor to highlight the script, and copy (type Control-c or Apple-c) the script into a new file in your text editor (such as Note Pad or Simple Text) and save (Control-s or Apple-s). The script is yours!!!

  <HEAD> <SCRIPT LANGUAGE="JavaScript">   <! > <! >  // Checks for the following valid date formats: // MM/DD/YY MM/DD/YYYY MM-DD-YY MM-DD-YYYY var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{4})$/; // requires 4 digit year var matchArray = dateStr.match(datePat); // is the format ok? if (matchArray == null) { alert("Date is not in a valid format.") return false; } month = matchArray[1]; // parse date into variables day = matchArray[3]; year = matchArray[4]; if (month < 1 || month > 12) { // check month range alert("Month must be between 1 and 12."); return false; } if (day < 1 || day > 31) { alert("Day must be between 1 and 31."); return false; } if ((month==4 || month==6 || month==9 || month==11) && day==31) { alert("Month "+month+" doesn't have 31 days!") return false; } if (month == 2) { // check for february 29th var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); if (day>29 || (day==29 && !isleap)) { alert("February " + year + " doesn't have " + day + " days!"); return false; } } return true; } function dispDate(dateObj) { month = dateObj.getMonth()+1; month = (month < 10) ? "0" + month : month; day = dateObj.getDate(); day = (day < 10) ? "0" + day : day; year = dateObj.getYear(); if (year < 2000) year += 1900; return (month + "/" + day + "/" + year); } function pregnancyCalc(pregform) { menstrual = new Date(); // creates new date objects ovulation = new Date(); duedate = new Date(); today = new Date(); cycle = 0, luteal = 0; // sets variables to invalid state ==> 0 if (isValidDate(pregform.menstrual.value)) { // Validates menstual date menstrualinput = new Date(pregform.menstrual.value); menstrual.setTime(menstrualinput.getTime()) } else return false; // otherwise exits cycle = (pregform.cycle.value == "" ? 28 : pregform.cycle.value); // defaults to 28 // validates cycle range, from 22 to 45 if (pregform.cycle.value != "" && (pregform.cycle.value < 22 || pregform.cycle.value > 45)) { alert("Your cycle length is either too short or too long for \n" + "calculations to be very accurate! We will still try to \n" + "complete the calculation with the figure you entered. "); } luteal = (pregform.luteal.value == "" ? 14 : pregform.luteal.value); // defaults to 14 // validates luteal range, from 9 to 16 if (pregform.luteal.value != "" && (pregform.luteal.value < 9 || pregform.luteal.value > 16)) { alert("Your luteal phase length is either too short or too long for \n" + "calculations to be very accurate! We will still try to complete \n" + "the calculation with the figure you entered. "); } // sets ovulation date to menstrual date + cycle days - luteal days // the '*86400000' is necessary because date objects track time // in milliseconds; 86400000 milliseconds equals one day ovulation.setTime(menstrual.getTime() + (cycle*86400000) - (luteal*86400000)); pregform.conception.value = dispDate(ovulation); // sets due date to ovulation date plus 266 days duedate.setTime(ovulation.getTime() + 266*86400000); pregform.duedate.value = dispDate(duedate); // sets fetal age to 14 + 266 (pregnancy time) - time left var fetalage = 14 + 266 - ((duedate - today) / 86400000); weeks = parseInt(fetalage / 7); // sets weeks to whole number of weeks days = Math.floor(fetalage % 7); // sets days to the whole number remainder // fetal age message, automatically includes 's' on week and day if necessary fetalage = weeks + " week" + (weeks > 1 ? "s" : "") + ", " + days + " days"; pregform.fetalage.value = fetalage; return false; // form should never submit, returns false } // End --> </script> </HEAD>  <BODY> <center> <form onSubmit="return pregnancyCalc(this);"> <table> <tr><td> <pre> Last Menstrual Period: <input type=text name=menstrual value="" size=10 maxlength=10> (MM/DD/YYYY format) Average Length of Cycles: <input type=text name=cycle value="" size=3 maxlength=3> (22 to 45) (defaults to 28) Average Luteal Phase Length: <input type=text name=luteal value="" size=3 maxlength=3> (9 to 16) (defaults to 14) <center><input type=submit value="Calculate!"></center> Estimated Conception: <input type=text name=conception value="" size=20> Estimated Due Date: <input type=text name=duedate value="" size=20> Estimated Fetal Age: <input type=text name=fetalage value="" size=20> </pre> </td></tr> </table> </form> </center>