I reckon walking pace is probably closer to 2500 steps per mile.
So at a brisk pace you’d cover 4 miles in one hour which would equal your 10,000 steps for the day
Quick google says that at 4mph calories burnt should be in the region of 468kcal
Cycling for one hour at 12-14mph = 792kcal so cycling at that pace for 35 minutes would give you the same calorie count as the brisk walk above, in this time you’d cover 8.26 miles (at 14mph).
Now to keep the math’s simple lets round that down to 8 miles which conveniently is twice the distance that it’s taken to burn those calories by walking.
So by my reckoning you should have to travel 2 miles on the bike for every 1 mile travelled on foot.
or to put it another way 1 mile on the bike = 1,250 steps [edit] or 777 steps per kilometre by bike.
[extra edit] By that fag packet calculation 10,000 walking steps = 12.8 km on the bike.