Seven calculators a field engineer actually reaches for — running live in your browser, free, no sign-up. Each one shows the formula and the standard behind it, so you can see exactly where the number comes from. Measured, not guessed.
| API No. | Cut-point | Removes |
|---|---|---|
| API 40 | 420 µm | Coarse — gravel/large cuttings |
| API 60 | 250 µm | Coarse sand |
| API 80 | 180 µm | Medium sand |
| API 100 | 150 µm | Medium sand |
| API 120 | 125 µm | Fine sand |
| API 140 | 106 µm | Fine sand |
| API 170 | 90 µm | Very fine sand |
| API 200 | 75 µm | Coarse silt / barite-friendly |
| API 230 | 63 µm | Silt |
| API 270 | 53 µm | Fine silt |
| API 325 | 45 µm | Fine silt — barite recovery limit |
| Blend fraction | Target size | Role |
|---|
These calculators are field aids for quick checks and decisions, not a substitute for a full engineering review. Results depend on the inputs you give and on assumptions noted under each tool. For anything load-bearing — a weight-up programme, a dilution plan, a hydrocyclone or shaker set-up on a live well — have it validated against your actual fluid, equipment and well conditions.
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These tools tell you what the formulas say. A field evaluation tells you what your shakers, hydrocyclones, centrifuge and mud system are actually doing — and what to change. That's the engineering.
See engineering services →Rig IQ works the solids-control and drilling-fluids math on your own rig data, then reads the numbers back as report-ready decisions — grounded in API RP 13C · 13B · 13D.
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