Milk fat and SNF calculator with your dairy’s rates
Dairy cooperatives and collection centres in India pay for milk by its fat and SNF (solids-not-fat: protein, lactose and minerals). Fat is measured by the Gerber test or a milk analyser; SNF is often worked out from the lactometer reading with a Richmond-type formula. This milk fat and SNF calculator does both steps: it turns a lactometer reading and fat % into SNF, total solids and specific gravity, then calculates the payment for any quantity of milk from your own rates per kg of fat and SNF.
Because states, unions and lactometers use slightly different SNF formulas, you can pick a common one or type your dairy’s fat factor and constant. A two-axis rate chart — fat down the side, SNF across the top — can be built for any range and downloaded as CSV, so you can check the chart pinned up at your society.
How to use the milk fat and SNF calculator
- Type the fat % from your slip or test. Then enter the lactometer reading and milk temperature, or switch to I know SNF if the analyser printed it.
- Choose the SNF formula your dairy uses, or type its fat factor and constant. Keep temperature correction on unless your reading is already corrected.
- Under Milk payment, pick the pricing method, the quantity in litres or kg, and your ₹ per kg fat and SNF (or per kg total solids).
- Read the amount, the price per litre and per kg, and the kg of fat and SNF behind it.
- Open Rate chart, set the fat and SNF ranges and steps, and download it as CSV if you want to print it.
Milk Fat & SNF Calculator features
SNF from CLR
SNF = CLR/4 + fat factor × fat + constant, with presets for the common variants and a custom option.
Temperature correction
Adjusts the lactometer reading by about 0.2 per °C away from its calibration temperature.
Three pricing methods
Two-axis fat + SNF rates, fat-only rates, or a rate per kg of total solids.
Litres or kg
Converts litres to kg with the specific gravity from the CLR (about 1.03 kg per litre).
Rate chart and CSV
A fat × SNF price grid per kg or per litre, with your sample highlighted.
SNF formulas in use
State-wise variants come from a 2017 trade compilation, not an official notification, and other unions use constants from 0.14 to 0.70 — always use your dairy’s own formula. The CLR is the lactometer reading corrected for temperature; specific gravity is 1 + CLR/1000.
| Formula | Lactometer temperature | Where it is reported |
|---|---|---|
| SNF = CLR/4 + 0.21 × fat + 0.36 | 15.5–27 °C, by state | Gujarat, Maharashtra, Goa, Andhra Pradesh, West Bengal, Odisha |
| SNF = CLR/4 + 0.20 × fat + 0.36 | 29 °C | ICAR e-course on dairy chemistry |
| SNF = CLR/4 + 0.25 × fat + 0.44 | 27 °C | Listed for the BIS lactometer |
| SNF = CLR/4 + 0.20 × fat + 0.14 | 15.5 °C (60 °F) | Richmond’s original formula |
Worked example
Cow milk with 4.0% fat and a corrected lactometer reading of 28: SNF = 28/4 + 0.21 × 4.0 + 0.36 = 7.00 + 0.84 + 0.36 = 8.20%, and total solids are 12.20%. Ten litres weigh 10 × 1.028 = 10.28 kg, containing 0.411 kg of fat and 0.843 kg of SNF.
At an example rate of ₹420 per kg fat and ₹280 per kg SNF, the payment is 0.411 × 420 + 0.843 × 280 = ₹408.73, or ₹40.87 per litre. If the reading were taken at 32 °C on a 27 °C lactometer with LR 27, adding 0.2 × 5 = 1 gives the same CLR of 28.
Two-axis pricing in brief
Under two-axis pricing, promoted by NDDB for cooperatives, a dairy announces one rate per kg of fat and one per kg of SNF, usually linked to the market value of ghee and skim milk powder. Milk richer in either component earns more, and the farmer can see exactly why. Some unions pay on fat alone (often for buffalo milk) or on total solids. To balance the feed that drives fat and SNF, try the cattle feed calculator.
Milk Fat & SNF Calculator FAQ
What is the SNF formula?
The widely used Richmond-type formula is SNF = CLR/4 + 0.21 × fat + 0.36, where CLR is the corrected lactometer reading. Some dairies use 0.20 or 0.25 for the fat factor and a different constant.
How do I calculate SNF from CLR and fat?
Divide the CLR by 4, add the fat % multiplied by the fat factor, then add the constant. CLR 28 and fat 4.0% give 7 + 0.84 + 0.36 = 8.20% SNF.
How is milk rate calculated from fat and SNF?
kg of milk × fat % × rate per kg fat + kg of milk × SNF % × rate per kg SNF. The milk fat and SNF calculator shows each part.
What is CLR in milk?
The corrected lactometer reading: the lactometer reading adjusted to the temperature the lactometer was calibrated at. Specific gravity = 1 + CLR/1000.
How many kg is one litre of milk?
About 1.03 kg for whole milk — specific gravity is usually between 1.028 and 1.032. The calculator uses the value from your CLR.
Why does my dairy’s SNF differ from this calculator?
They may use another formula constant, a corrected reading, or a milk analyser that measures SNF directly. Choose Custom and type their formula, or switch to I know SNF.