We're always being told to count our units and make sure we don't drink too much, but how many of us actually know how many units of alcohol are in our regular drinks?

So, whether you're a fan of bottled beers, a glass of red or a quick gin and tonic, let us help you understand how many units of alcohol are in which drinks...

The guidelines

The advice from the Department of Health is:

Men should drink no more than 21 units of alcohol per week (and no more than four units in any one day). Women should drink no more than 14 units of alcohol per week (and no more than three units in any one day).

In general, the more you drink above the safe limits, the more harmful alcohol is likely to be. And remember, binge drinking can be harmful even though the weekly total may not seem too high.

For example, if you only drink once or twice a week, but when you do you drink 4-5 pints of beer each time, or a bottle of wine each time, then this is a risk to your health.

How many units are you drinking?

One unit of alcohol is 10 ml (1 cl) by volume, or 8 g by weight, of pure alcohol.

It's the strength and size of a drink that determines how many units it has. It's not as simple as one drink, one unit.

So, on average, one alcohol unit translates to the following:

Half a pint of ordinary strength beer, lager, or cider - 3-4% alcohol by volume (ABV) A small pub measure (25 ml) of spirits, such as gin, vodka or whisky - 40% ABV A standard pub measure (50 ml) of fortified wine such as sherry or port - 20% ABV.

But as not many of us drink halves of beer now and most pubs serve larger measures than they used to, it's become more and more difficult to work out your units.

Beers

A more accurate way of calculating units is as follows. The percentage alcohol by volume (%ABV) of a drink equals the number of units in one litre of that drink. A normal bottle (330ml) of strong lager, such as Becks or Budweiser (5% ABV) = 1.7 units. A pint of strong lager (568ml), such as Stella (5.2% ABV) = 3 units.

Bitter is less strong, generally, than lager. A pint of bitter is less strong (3.5-4.0% ABV) = 2 units.

However, just two pints will put you over the government-recommended maximum daily drinks allowance of 2-3 units for women.

Spirits

A standard pub measure of spirits is now 35ml, so there are actually 1.5 units of alcohol in a normal vodka and orange or G&T.

Many bars also serve double measures as standard practice, so be careful when you order. You are likely to be drinking more than you think.

Wine

This is where a lot of the controversy has come in. Ten years ago, nearly all wine was served in small glasses of 125ml.

In one small glass or ordinary-strength wine (12% ABV), there are one-and-a-half units of alcohol.

However, a standard-size glass of wine in a pub is now 175ml and many places offer 250ml glasses - this is the equivalent of a third of a bottle. This inevitably means many people drink far more than they used to. In one standard glass (175ml) of ordinary-strength wine, there are 2.3 units of alcohol: so just two glasses will be almost 5 units of alcohol. In one 250ml glass of ordinary-strength wine, there are 3 units.

Other drinks

Bottles of mixer drinks, such as Bacardi Breezer and Smirnoff Ice are also very popular.

A bottle (275ml at 5-5.5% ABV) is 1.5 units, so just two bottles will put you at the top of the government-recommended maximum daily drinks allowance of 2-3 units for women.