How to: Convert Between Metric and US Units of Measurement

• Sep 19, 2023
• 3 minutes to read

This example illustrates the use of a QuantityValue<T> object and the Unit Conversion API converters for calculating the volume and the mass of the water in the aquarium tank; followed by a display of the results using US and metric units.

Form1.cs

using DevExpress.UnitConversion;
//Quantity value is a value measured in a certain unit.
//You cannot mix different quantity values in a single expression.
//Instead, you can easily convert them as required and use the Value property to obtain numerical values.
QuantityValue<Distance> l = (48.25).Inches();
QuantityValue<Distance> w = (12.75).Inches();
QuantityValue<Distance> h = (21.0).Inches();
QuantityValue<Volume> vol = (l.ToMeters().Value * w.ToMeters().Value * h.ToMeters().Value).CubicMeters();
QuantityValue<Mass> m = (vol.ToLiters() * 1000).Value.Grams();
QuantityValue<Pressure> loading = (m.ToPounds() / (l * w).Value.SquareInches()).Value.PoundsPerSquareInch();
//US Standard uniform floor load is 0.2 psi.
double percentageUS = loading.ToPoundsPerSquareInch() / (0.2).PoundsPerSquareInch() * 100;
//British standard imposed load is 1500 Newtons per square meter.
double percentageEu = loading.ToPascals() / (1500.0).Pascals() * 100;

string textFormatUS = "The aquarium tank (length {0:g3} in, width {1:g3} in, height {2:g3} in) contains {3:g5} gallons of water. " +
"It weights {4:g5} lbs. " +
"The pressure at the bottom is {5:g3} percent of the standard US wood joist floor loading.";
string textUS = String.Format(textFormatUS, l.ToInches().Value, w.ToInches().Value,
    h.ToInches().Value, vol.ToGallons().Value, m.ToPounds().Value, percentageUS);

string textFormatEu = "The aquarium tank (length {0:g3} m, width {1:g3} m, height {2:g3} m) contains {3:g5} liters of water. " +
"It weights {4:g5} kg. " +
"The pressure at the bottom is {5:g3} percent of the standard UK wood joist floor loading.";
string textEu = String.Format(textFormatEu, l.ToMeters().Value, w.ToMeters().Value,
    h.ToMeters().Value, vol.ToLiters().Value, m.ToKilograms().Value, percentageEu);

string msg = radioButtonUS.Checked ? textUS : textEu;
MessageBox.Show(msg);

Form1.vb

Imports DevExpress.UnitConversion
'Quantity value is a value measured in a certain unit.
'You cannot mix different quantity values in a single expression.
'Instead, you can easily convert them as required and use the Value property to obtain numerical values.
Dim l As QuantityValue(Of Distance) = (48.25).Inches()
Dim w As QuantityValue(Of Distance) = (12.75).Inches()
Dim h As QuantityValue(Of Distance) = (21.0).Inches()
Dim vol As QuantityValue(Of Volume) = (l.ToMeters().Value * w.ToMeters().Value * h.ToMeters().Value).CubicMeters()
Dim m As QuantityValue(Of Mass) = (vol.ToLiters() * 1000).Value.Grams()
Dim loading As QuantityValue(Of Pressure) = (m.ToPounds() / (l * w).Value.SquareInches()).Value.PoundsPerSquareInch()
'US Standard uniform floor load is 0.2 psi.
Dim percentageUS As Double = loading.ToPoundsPerSquareInch() / (0.2).PoundsPerSquareInch() * 100
'British standard imposed load is 1500 Newtons per square meter.
Dim percentageEu As Double = loading.ToPascals() / (1500.0).Pascals() * 100

Dim textFormatUS As String = "The aquarium tank (length {0:g3} in, width {1:g3} in, height {2:g3} in) contains {3:g5} gallons of water. " & "It weights {4:g5} lbs. " & "The pressure at the bottom is {5:g3} percent of the standard US wood joist floor loading."
Dim textUS As String = String.Format(textFormatUS, l.ToInches().Value, w.ToInches().Value, h.ToInches().Value, vol.ToGallons().Value, m.ToPounds().Value, percentageUS)

Dim textFormatEu As String = "The aquarium tank (length {0:g3} m, width {1:g3} m, height {2:g3} m) contains {3:g5} liters of water. " & "It weights {4:g5} kg. " & "The pressure at the bottom is {5:g3} percent of the standard UK wood joist floor loading."
Dim textEu As String = String.Format(textFormatEu, l.ToMeters().Value, w.ToMeters().Value, h.ToMeters().Value, vol.ToLiters().Value, m.ToKilograms().Value, percentageEu)

Dim msg As String = If(radioButtonUS.Checked, textUS, textEu)
MessageBox.Show(msg)

For a US location, the output string looks like the following.

For a UK location, the output string looks like the following.