Example:-
Task: How many sq.rods in 10 acres.
From the tables: 1 acre = 160 sq.rods, so
10 acres x 160 = 1600 sq.rods
When you want to reverse the conversion,
divide by the factor viz.
1600 sq.rods/160 = 10 acres

Convert Fractions of an Inch to mm
Two pages convert feet, inches and fractions of an inch to metric and from metric to feet inches and tenths of an inch. Easier than getting an answer in 6.7238 feet!

Impossible Conversions
Remember that you cannot create energy only convert it. Likewise, you will not find a conversion from pounds to metres - the basic units must remain the same - mass converted to mass, length converted to length, and so on. A common question is... How many horsepower in a 500cc engine which is an impossible conversion but I have given an approximation on this page.

You won't usually find a conversion from kilograms to grams - the prefix 'kilo' means '1,000' so a kilogram is in fact 1,000 grams in the same way as a kilometer is 1,000 metres [or about 1,000 yards in 'old money']. I have put a few in the table because visitors have asked for them. More examples can be found on the prefix table.

One handy metric link between units
Remember that 1 Litre [1000cc] of pure water weighs 1 kilogram.
Equally, 1 milliliter of pure water has a mass of 1 gram or 1mL = 1g.
The upper case L for liter is preferable as the lower case can be confused with the figure one, however it is common to see ml for milliliters on bottles.

The scientific notation - 1.76E+09 or 3.78E-12 cuts out a lot of noughts. Explained here ...

If accuracy is critical beware of old versions of MS Excel which had problems rounding off numbers.

We have tried to be accurate with the data but cannot be held responsible for inaccuracies.
Go back to first principals and double check your calculations if the result is 'mission critical'.

Metrication is a great help but has also created anomalies; I have seen pressure gauges changed from a commonly used psi to kg/cm.sq., bar, pascal, kPa and atmos but will no doubt move to a popular metric standard in a few decades.

More information on the SI System (Le Système International d'Unités) base units and definitions.

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