Regreasing interval and grease amount calculator
Enter your bearing and operating conditions. You get the hours between regreasing, the grease shot in grams, and the yearly grease use for the bearing.
Worked example
Inputs: deep groove ball bearing, normal load (C/P 8), 40 mm bore, 90 mm outside diameter, 23 mm width, 1,450 rpm, 70 °C, clean and dry.
- Shot size from the side: about 10.4 g (roughly 11.6 cm³). Through holes in the middle of the outer ring: about 4.1 g.
- First fill: pack the bearing full and fill about 40% of the free space in the housing (20% if the grease is fed through the centre).
- At 24-hour running this uses roughly 11 g per year per bearing.
This is the live calculator output for the default values above.
How it works
- The interval comes from the grease-life nomograph method: it is read from curves of speed × mean diameter × a bearing-type factor, for three load levels (C/P 4, 8 and 15), and interpolated between them.
- The reference temperature is 70 °C. For every 15 °C above that the interval roughly halves.
- Dusty or wet conditions halve it again.
- The result is capped at 30,000 hours.
- Grease shot from the side: 0.005 × D × B grams (D and B in mm). Through holes in the middle of the outer ring it is 0.002 × D × B.
- First fill: pack the bearing and fill about 40% of the housing free space (20% if fed through the centre).
Good practice
Add grease slowly with the machine running where it is safe, and leave the drain open until the old grease has left. If the interval comes out under 500 hours, consider a centralised greaser, a continuous lubricator or oil.
Related tools and guides
Questions
How often should I grease a bearing?
It depends on speed, size, load, temperature and cleanliness. The calculator gives hours for your bearing. For a 40 × 90 mm deep groove bearing at 1,450 rpm, 70 °C, normal load and clean conditions, the calculator gives about 8,400 hours.
How much grease should I add to a bearing?
A common starting shot from the side is 0.005 × D × B grams, where D is outside diameter and B is width, both in mm. Adjust by watching grease behaviour and temperature.
Does temperature change the greasing interval?
Yes. As a rule the interval halves for every 15 °C above 70 °C.
Results are starting points from standard engineering practice. Confirm critical selections with the bearing or lubricant maker.