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Free printable dip chart

1,200 litre oil tank Dip Chart

A 1,200 litre oil tank holds about 1,208 litres full and roughly 1,027 litres at the 85% safe fill. A dip reading of 43cm on this upright rectangular tank is about 406 litres, or 34% full, so topping up to safe fill would mean ordering about 621 more litres.

Your reading

Tank make or size

Units

Dip reading, oil depth from the bottom (cm)

Typical daily usage (litres)

Price per litre (pence, optional)

Use the price from your latest quote or invoice to see a fill cost. Leave blank for litres only.

What you have

Oil remaining

339litres

About 34% full of a 999 litre tank.

Days of heating left

28 days

At your stated daily usage.

Litres to fill to safe fill

510 litres

Enter a price per litre on the left to see the cost to reach the 85% safe fill.

About the 1,200 litre oil tank

The 1,200 litre tank suits larger three and four-bedroom homes. This slimline upright shape is popular where garden space is tight, and it fills roughly linearly with depth.

This tank holds about 1,208 litres full, with a 85% safe fill near 1,027 litres. A dip reading of 43cm works out at roughly 406 litres, or 34% full. Topping up to safe fill from there is about 621 litres. Enter your own price per litre in the calculator above to turn that into a cost.

Full printable dip chart

Every 5cm of oil depth for the 1,200 litre oil tank. Print this and keep it by the tank.

Depth (cm)	Litres	% full
5	47	4%
10	94	8%
15	142	12%
20	189	16%
25	236	20%
30	283	23%
35	330	27%
40	378	31%
45	425	35%
50	472	39%
55	519	43%
60	566	47%
65	614	51%
70	661	55%
75	708	59%
80	755	63%
85	802	66%
90	850	70%
95	897	74%
100	944	78%
105	991	82%
110	1,038	86%
115	1,086	90%
120	1,133	94%
125	1,180	98%
128	1,208	100%

How this is calculated

Upright / rectangular tank (linear with depth):
  litres = capacity x (depth / full_height)

This tank: width 118cm, height 128cm, length 80cm
  capacity  = 1208 litres
  safe fill = 1208 x 0.85 = 1027 litres

Example: depth 43cm -> 406 litres (34% full)

Figures used on this page

Figure	Value	Source	Verified
tank safe fill pct	0.85 ratio	OFTEC guidance: tanks are filled to 80-90% of stated capacity to allow expansion	2026-07-28
vat domestic	0.05 ratio	VAT Act 1994 Schedule 7A Group 1, domestic fuel reduced rate	2026-07-28

What affects the result

Make and exact dimensions. The figures here are for representative internal dimensions of a 1,200 litre oil tank. Different makes vary by a few centimetres, so if your dip reading seems out of step, measure your own tank and use the custom builder.

Shape. This is an upright tank that fills close to linearly, so depth and litres track fairly evenly from bottom to top.

Safe fill. Order to the 85% figure of about 1,027 litres rather than the brim, so the oil has room to expand and the vent does not overflow during delivery.

Reading conditions. Keep the rod vertical and resting on the base, and allow for a little sludge at the bottom of an older tank. Treat the very lowest readings as a warning to reorder rather than a precise measure.

1,200 litre oil tank Dip Chart FAQs

How many litres is a 1200 litre tank when full?

Its stated capacity is 1,200 litres and this model works out at about 1,208 litres from typical internal dimensions. In practice you fill to around 85%, roughly 1,027 litres, to allow for expansion.

How do I read the dip chart for this tank?

Dip the tank with a clean straight rod, read the wet depth in centimetres, then find that row in the chart below. It converts the depth to litres and a percentage for this specific 1,200 litre upright rectangular tank.

Which makes match this size?

Common 1,200 litre models include Harlequin 1200ISO, Kingspan Titan 1200, Carbery 1200H. Dimensions vary a little between makes, so if your reading looks off, build a custom chart from your own measurements in the calculator above.

How many litres does it take to fill this tank?

Filling from a 43cm reading to the 85% safe level is about 621 litres. A full empty-to-safe fill takes about 1,027 litres. Enter your own price per litre in the calculator to turn either figure into a cost.

Is the dip reading linear on this tank?

Roughly, yes. This upright tank fills close to linearly, so half the depth is close to half the litres. The chart still gives you the exact litres at each 5cm without any mental arithmetic.