Well high. You make no allowance for diversity. Many of the ratings quoted
are well above the currents actually likely to be drawn. Also, they are peak
currents. Most will only draw these for short periods, which are unlikely to
be exactly coincident in time. Also, short transient currents above the
rating are permitted. It is only if the current remains over the rated
current for a long time (i.e. minutes) will it matter.

12.5A (Washing machine)

Only whilst heating water, which might be for ten minutes at a time. Average
current much lower.

14.5A (Tumble dryer)

Again, average current is lower. The rating you give is actually above the
13A fuse, so is too high.

6A (Iron)

Low duty cycle. Mine only comes on for a few seconds before cutting out for
a minute. Average current much lower.

1.5A (Fridge)

Again, low duty cycle. The compressor only comes on occasionally.

3A (Freezer)

I don't believe a freezer would draw 3A on average.

12A (Dishwasher)

Only whilst heating, which isn't very much.

10A (Cooker (electric))

If cooking a complex dinner, the average might exceed this.

6A (Microwave oven)

Only for a couple of minutes.

8A (Electric kettle)

Only for a couple of minutes.

2A (Hi-Fi Stereo, surround sound system.)

Hope you don't have neighbours. That would produce about 125W rms per
channel on a 50% efficient amplifier, which would blow your ears off, unless
you wear baseball caps backwards.

2A (2 x Computer)
1A (Computer)

Well over. The power supply is its maximum rating. It will only draw a
fraction.

1A (2 x 17" monitor)
0.5A (17" monitor)

Probably about right.

6A (Hair dryer)

Only used for a couple of minutes at a time.

2A (Shower pump)

Only used for a couple of minutes at a time.

2A (Extractor fan)

Only used for a couple of minutes at a time. This rating will produce a
hurricane.

12.5A (Immersion or water heater)

Should only be used for backup. You do have central heating that heats the
water? It is also thermostatically controlled, so isn't a constant load.

3.5A (Central heating pump)

This is totally way over the top. Normally, the entire central heating
system is fused at 3A.

3A (Fan Heater 1/3hp)

That's a very little heater. However, it could be a reasonable average in a
centrally heated home with thermostatic control.

10A (Lighting)

Does this include floodlighting the football pitch? I have about 10 bulbs,
with an average wattage of around 15W, giving 150W ~= 0.6A. Even if you have
tonnes of halogen lighting, I'd be surprised to see a figure this high. This
is 2.4kW of bulbs, or 24 100W bulbs, all on simultaneously.

5A (Sundry electrical loads)

That's a total 124.5 amps. OK, we can argue that their approach to energy
efficiency could be improved. In terms of rating a supply, however, a
single
phase 100A supply seems inadequate.

This would absolutely covered by diversity calculations. You could probably
squeeze it into a 60A supply. Remember, it doesn't matter if the
instantaneous current exceeds 100A for a short period. It is the average
current drawn over a period of minutes that counts. I doubt that these loads
in actual use (rather than pathological timing) would actually exceed 60A).

Christian.