Walking from Big Ben to Piccadilly Circus

Q: For a fun quiz that I'm doing, can you tell me how long it would take me to walk from Big Ben to Piccadilly Circus if I took the route:

Big Ben -> White Hall -> Trafalgar Square -> Leicester Square ->

Piccadilly Circus

A: I suggest it would probably take you 30 - 40 mins to do (ignoring any stops). As follows (but only my guesstimates!):

from Big Ben, along Whitehall to Trafalgar Square: 10 - 15 minutes

from Trafalgar Square, up Charing Cross Road to Leicester Square: 10 minutes +

Through Leicester Square to Piccadilly Circus: 10 minutes +