function calculateDistanceRateTime() {
var distance = parseFloat(document.getElementById("distance").value);
var rate = parseFloat(document.getElementById("rate").value);
var time = parseFloat(document.getElementById("time").value);
var distanceUnit = document.getElementById("distanceUnit").value;
var rateUnit = document.getElementById("rateUnit").value;
var timeUnit = document.getElementById("timeUnit").value;
var resultElement = document.getElementById("result");
resultElement.innerHTML = ""; // Clear previous results
// — Unit Conversion Factors (to a common base for calculation) —
// Base: Meters for distance, Seconds for time, Meters per Second for rate
var distanceInMeters = 0;
switch (distanceUnit) {
case "miles":
distanceInMeters = distance * 1609.34;
break;
case "kilometers":
distanceInMeters = distance * 1000;
break;
case "meters":
distanceInMeters = distance;
break;
case "feet":
distanceInMeters = distance * 0.3048;
break;
}
var timeInSeconds = 0;
switch (timeUnit) {
case "hours":
timeInSeconds = time * 3600;
break;
case "minutes":
timeInSeconds = time * 60;
break;
case "seconds":
timeInSeconds = time;
break;
}
var rateInMetersPerSecond = 0;
switch (rateUnit) {
case "mph":
rateInMetersPerSecond = rate * 1609.34 / 3600;
break;
case "kph":
rateInMetersPerSecond = rate * 1000 / 3600;
break;
case "mps":
rateInMetersPerSecond = rate;
break;
case "fps":
rateInMetersPerSecond = rate * 0.3048;
break;
}
// — Calculations —
var calculatedDistance = 0;
var calculatedRate = 0;
var calculatedTime = 0;
if (!isNaN(rate) && !isNaN(time)) {
calculatedDistance = rateInMetersPerSecond * timeInSeconds;
// Convert calculated distance back to original distance unit if distance was not an input
if (isNaN(distance)) {
switch (distanceUnit) {
case "miles":
calculatedDistance /= 1609.34;
break;
case "kilometers":
calculatedDistance /= 1000;
break;
case "meters":
// already in meters
break;
case "feet":
calculatedDistance /= 0.3048;
break;
}
resultElement.innerHTML += "Calculated Distance: " + calculatedDistance.toFixed(2) + " " + distanceUnit + "";
}
}
if (!isNaN(distance) && !isNaN(time)) {
calculatedRate = distanceInMeters / timeInSeconds;
// Convert calculated rate back to original rate unit if rate was not an input
if (isNaN(rate)) {
switch (rateUnit) {
case "mph":
calculatedRate *= 3600 / 1609.34;
break;
case "kph":
calculatedRate *= 3600 / 1000;
break;
case "mps":
// already in mps
break;
case "fps":
calculatedRate /= 0.3048;
break;
}
resultElement.innerHTML += "Calculated Rate: " + calculatedRate.toFixed(2) + " " + rateUnit + "";
}
}
if (!isNaN(distance) && !isNaN(rate)) {
calculatedTime = distanceInMeters / rateInMetersPerSecond;
// Convert calculated time back to original time unit if time was not an input
if (isNaN(time)) {
switch (timeUnit) {
case "hours":
calculatedTime /= 3600;
break;
case "minutes":
calculatedTime /= 60;
break;
case "seconds":
// already in seconds
break;
}
resultElement.innerHTML += "Calculated Time: " + calculatedTime.toFixed(2) + " " + timeUnit + "";
}
}
if (isNaN(distance) && isNaN(rate) && isNaN(time)) {
resultElement.innerHTML = "Please provide at least two values to calculate the third.";
} else if (distance === 0 || rate === 0 || time === 0) {
resultElement.innerHTML = "Input values cannot be zero for calculation in this context.";
} else if (isNaN(distance) && isNaN(rate) || isNaN(distance) && isNaN(time) || isNaN(rate) && isNaN(time)) {
// This case is handled above when calculating one missing value
}
}
Understanding Distance, Rate, and Time
The relationship between distance, rate (or speed), and time is a fundamental concept in physics and mathematics. It's often expressed by the formula: Distance = Rate × Time.
The Core Formula Explained
- Distance: This is the total length or span covered by an object's movement. It can be measured in units like miles, kilometers, meters, feet, etc.
- Rate (Speed): This measures how quickly an object is moving. It's typically expressed as distance per unit of time (e.g., miles per hour (mph), kilometers per hour (kph), meters per second (mps), feet per second (fps)).
- Time: This is the duration for which the movement occurs. It's measured in units like hours, minutes, or seconds.
How the Calculator Works
This calculator allows you to find any one of these three values if you provide the other two. For instance:
- If you know the rate and time, you can calculate the distance traveled.
- If you know the distance and time, you can calculate the required rate (speed).
- If you know the distance and rate, you can calculate the time it will take.
The calculator handles different units of measurement for distance, rate, and time. It converts all inputs to a common base unit (meters for distance, seconds for time, and meters per second for rate) to perform the calculation accurately, and then converts the result back to your desired output unit.
Example Calculation
Let's say a car travels at a constant speed of 60 miles per hour (mph) for 2.5 hours.
- Distance: Not provided (to be calculated)
- Rate: 60 mph
- Time: 2.5 hours
Using the formula, Distance = 60 mph × 2.5 hours = 150 miles.
If you input "60" for Rate (in mph) and "2.5" for Time (in hours), the calculator would output "150.00 miles" for the Distance.
Another example: If a package needs to travel 500 kilometers and the maximum allowed time is 10 hours, what is the minimum average speed (rate) required?
- Distance: 500 kilometers
- Rate: Not provided (to be calculated)
- Time: 10 hours
Using the formula rearranged: Rate = Distance / Time. Rate = 500 km / 10 hours = 50 kph.
Inputting "500" for Distance (in kilometers) and "10" for Time (in hours) would result in the calculator showing a calculated Rate of "50.00 kph".