The reckonerFour calculators. They run in the page — the arithmetic is printed under each one so you can check it on paper.
How fast are you goin' settin' still?
What the air is costin' you
Addin' two speeds, the correct way
How slow does the watch run?
Where these come from
The porch speed is the circumference of your line of latitude divided by a sidereal day, plus the Earth's orbit, plus the Sun's trip around the galaxy — each one measured against a different thing, which is the point of the first page.
The air cost is P = ½ρv³CdA with ρ falling off by the standard atmosphere. It is the air only: tyres, driveline and hills are on top.
The other two are (u+v)/(1+uv/c²) and γ = 1/√(1−v²/c²), which is the whole of the ceilin' in two lines.