As the world's biggest particle accelerator prepares to crank up its proton beams, Nature rounds up the big numbers behind the mother of all atom smashers.
- 27 kilometres = circumference of the LHC.
- 50 kilometres per hour = speed limit for physicists on site.

- 32 minutes = time taken by a law-abiding physicist to circle the ring.
- ~1 billion kilometres per hour (99.9999991% the speed of light) = maximum proton speed around the ring.
- One ten-thousandth of a second = time taken by proton to circle the ring.
- 0.00000000047 grams = total mass of protons circulating in the LHC at any time.
- 362 megajoules = collective energy of LHC's protons at top speed.

- 88,000 tonnes = total weight of the aircraft carrier USS Ronald Reagan.
- 361 megajoules = energy of the USS Ronald Regan when cruising at 5.6 knots.
- US$4.1 billion = cost of building the LHC.
- US$4.5 billion = cost of the USS Ronald Regan.
- ~9,000 cubic metres = total volume of the LHC's major vacuum systems.
- 4,650 cubic metres = interior volume of the Big Ben clock tower at Westminster.
- 14 years = time taken to build LHC.
- 13 years = time taken to build Big Ben.

- ~6 million = number of DVDs needed to hold all of the data generated by the LHC.
- 6.9 kilometres = height of 4 million DVDs stacked on top of each other.
- 4.8 kilometres = height of Mount Blanc.
- 0.75 grams = amount of hydrogen needed to fill a party balloon.
- 0.000000002 grams = amount of hydrogen consumed each day by the LHC.
- ~1 million years = time needed for the LHC to use one party balloon's worth of hydrogen.
- 10-13 atmospheres = vacuum of the LHC's beamline.
- 10-12 atmospheres = atmospheric pressure on the Moon.
- 8.3 tesla = top field strength of each of the LHC's 1232 superconducting dipole magnets.
- 1 tesla = strength of a typical scrapyard electromagnet.