Cartridge calculator: silicone usage per joint

How many cartridges do you need? Enter the dimensions; the result includes 15 % loss for cutting, nozzle and rework.

2cartridges of 310 ml

Pure requirement 384 ml, with 15 % loss 442 ml.

Calculation: length [m] × width [mm] × depth [mm] = ml, triangle ÷ 2, + 15 % loss (up to 25 % depending on technique), rounded up to whole containers. Rule of thumb: depth = half the width from about 10 mm width, narrow joints roughly square (IVD data sheet). Guide value according to the manufacturer's data sheet, as of 01.10.2026.

Matching products

Ottoseal S100 Premium sanitary silicone joint white 300ml

joint white · €8.95 · Choose colour/version

Ottoseal S105 sanitary silicone manhattan 310ml

manhattan · €6.95 · Choose colour/version

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How much silicone you need per metre of joint and how far a cartridge goes: as a calculator and as a table to read off.

Usage table: silicone per metre of joint

The short answer: a 310 ml cartridge of silicone covers around 12 metres on a joint of 5 × 5 mm, around 6.5 metres at 8 × 6 mm and around 3.1 metres at 10 × 10 mm. Usage per metre is joint width times joint depth: 8 mm × 6 mm gives 48 ml of silicone per metre. In practice about 15 % is lost to cutting the nozzle, the nozzle itself and reworking, and up to 25 % depending on technique.

Silicone usage per metre and coverage per pack (rectangular joint)

Joint (width × depth)	Usage per metre	310 ml cartridge, calculated	310 ml cartridge, with 15 % loss	600 ml pack, with 15 % loss
4 × 4 mm	16 ml	19 m	17 m	33 m
5 × 5 mm	25 ml	12 m	11 m	21 m
6 × 6 mm	36 ml	8.6 m	7.5 m	14 m
8 × 6 mm	48 ml	6.5 m	5.6 m	11 m
8 × 8 mm	64 ml	4.8 m	4.2 m	8.2 m
10 × 8 mm	80 ml	3.9 m	3.4 m	6.5 m
10 × 10 mm	100 ml	3.1 m	2.7 m	5.2 m
12 × 10 mm	120 ml	2.6 m	2.2 m	4.3 m
15 × 10 mm	150 ml	2.1 m	1.8 m	3.5 m
20 × 12 mm	240 ml	1.3 m	1.1 m	2.2 m
25 × 12 mm	300 ml	1.0 m	0.9 m	1.7 m

How it is worked out: width (mm) × depth (mm) = millilitres per metre of joint. Joint depth is measured down to the backer rod. Figures rounded, no guarantee for irregular joints.

How much silicone do I need per metre?

As many millilitres as the width times the depth of the joint in millimetres: a 10 × 8 mm connection joint needs 80 ml per metre, a narrow 5 × 5 mm joint at the basin 25 ml per metre. For 10 metres of joint at 8 × 6 mm that is 480 ml, with losses around 550 ml, so two 310 ml cartridges.

How many metres does a cartridge cover on a triangular joint?

About twice as far. The triangular joint (a fillet, at the wall junction of a bath for instance) has half the cross-section of the rectangular joint: at 8 mm leg length it comes to around 32 ml per metre, so a 310 ml cartridge then covers just under 8.4 metres including losses. The calculator above handles both joint shapes.

How much primer do I need?

Primer usage depends on how absorbent the bonding flanks are and on how it is applied, and can only be given approximately. As a guide figure, 80 to 150 ml per square metre of bonding surface applies. The bonding surface is flank width times joint length times two flanks: at 10 mm flank width and 10 metres of joint that is 0.2 m², so with 100 ml/m² around 20 ml of primer. The exact figure is given by the primer's data sheet (OTTO Primer 1101, 1216, 1218, 1225).

Sealant requirement for window profiles

The following table gives an overview of minimum joint widths depending on the material of the window profiles and the element length.

Minimum joint widths B in mm

Material of the window profiles	Element length (butt reveal)				Element length (internal reveal)
Material of the window profiles	up to 1.5 m	up to 2.5 m	up to 3.5 m	up to 4.5 m	up to 2.5 m	up to 3.5 m	up to 4.5 m
Rigid PVC (white)	10	15	20	25	10	10	15
Rigid PVC and PMMA (dark, colour-extruded)	15	20	25	30	10	15	20
Rigid PUR integral foam	10	10	15	20	10	10	15
Timber-aluminium windows	10	10	15	20	10	10	15
Aluminium-plastic composite profiles (light)	10	10	15	20	10	10	15
Aluminium-plastic composite profiles (dark)	10	15	20	25	10	10	15
Timber window profiles	10	10	10	10	10	10	10

These minimum joint widths B also apply to interior connection joints for sealants with > 15 % permissible total deformation.

Joint sizing

A common rule of thumb for sizing joints is:

Sealant joint depth t = 0.5 × joint width b
The thickness of the joint sealant d corresponds to 2/3 of the joint width b

The ratio between the width of the sealant in the joint (b) and the depth of the sealant in the joint (t) should be as follows:

Joint width b (mm)	Joint depth t (mm)
10–15	8 ± 2
15–20	10 ± 2
20–25	12 ± 2
25–30	15 ± 3
30–35	15 ± 3

Source: Industrieverband Dichtstoffe e.V.