How to correctly calculate the width of the text?

Question

Delphi

How can I correctly calculate the width of the text using the Windows API?
The font is NOT monospaced. Arial.
For example: I have some string, let it be "Some string". I'm calculating the width using the GetTextExtentPoint32 function - correct. I calculate the width for the string "11111" - the result is greater than the actual width.
The cant reproduced only for Arial, but the option "Do not use Arial" is not suitable.

Answer 1

Used the DrawText function with the DT_CALCRECT flag

Answer 2

function TCustomCanvas.TextWidth(const Text: string): Integer;
begin
  Result := TextExtent(Text).cX;
end;
function TCanvas.TextExtent(const Text: string): TSize;
begin
  RequiredState([csHandleValid, csFontValid]);
  Result.cX := 0;
  Result.cY := 0;
  Winapi.Windows.GetTextExtentPoint32(FHandle, Text, Length(Text), Result);
end;