If you run a milk collection center, the single most common question farmers ask is: "How was my rate decided?" Milk is not priced per litre alone — it is priced on quality, measured mainly as FAT and SNF. This guide explains the two methods used across India to turn a FAT and SNF reading into a rupee amount, with worked examples you can follow on paper.
What FAT and SNF actually mean
Every litre of milk is water plus solids. Those solids split into two groups:
- FAT — the butterfat content, shown as a percentage. Buffalo milk has more fat than cow milk.
- SNF (Solids-Not-Fat) — everything solid that is not fat: protein, lactose (milk sugar), and minerals.
Higher FAT and higher SNF mean richer milk, so the rate goes up. Watery or adulterated milk shows low SNF and earns less.
The two main pricing methods
1. FAT-only method (rate per FAT point)
The simplest method, used by many private buyers. You fix a rate per unit of FAT and multiply:
Example: if your FAT rate is ₹8 per point and the milk tests at 4.0% FAT, then rate = 4.0 × 8 = ₹32 per litre. Easy to explain, but it ignores SNF — so thin, high-fat milk can be overpaid.
2. Two-axis method (FAT + SNF)
The standard used by most cooperatives and dairy unions, because it pays for total solids fairly. You set a separate rate for each kilogram of FAT and each kilogram of SNF, then price the actual solids in the milk:
Kg SNF = (Litres × SNF %) ÷ 100
Amount = (Kg FAT × FAT rate) + (Kg SNF × SNF rate)
Solved example (two-axis method)
A farmer brings 10 litres of milk testing 4.0% FAT and 8.5% SNF. The dairy's rates are ₹450 per kg FAT and ₹250 per kg SNF.
| Step | Calculation | Result |
|---|---|---|
| Kg FAT | (10 × 4.0) ÷ 100 | 0.40 kg |
| Kg SNF | (10 × 8.5) ÷ 100 | 0.85 kg |
| FAT value | 0.40 × ₹450 | ₹180.00 |
| SNF value | 0.85 × ₹250 | ₹212.50 |
| Total amount | ₹180 + ₹212.50 | ₹392.50 |
| Rate per litre | ₹392.50 ÷ 10 | ₹39.25 |
How to find SNF from a lactometer reading (CLR)
If you measure with a lactometer, you get the CLR (Corrected Lactometer Reading) and can derive SNF using a widely-used formula:
Example: CLR of 28 with 4.0% FAT gives SNF = (28 ÷ 4) + (0.25 × 4.0) + 0.44 = 7 + 1 + 0.44 = 8.44%. The constant (0.44) can vary slightly by region and standard, so confirm the version your union uses.
Typical FAT and SNF ranges
| Milk type | Usual FAT % | Usual SNF % |
|---|---|---|
| Cow milk | 3.0 – 4.5 | 8.0 – 9.0 |
| Buffalo milk | 6.0 – 8.0 | 9.0 – 10.0 |
| Mixed / bulk | 4.0 – 6.0 | 8.5 – 9.5 |
Readings far below these ranges usually signal added water or poor animal health — worth flagging at collection.
Why the same milk earns different rates elsewhere
Two dairies can quote different amounts for identical milk because:
- They use different FAT and SNF rates tied to their own selling price.
- One uses FAT-only pricing while the other uses two-axis.
- Rounding rules and quality incentives differ.
This is exactly why a transparent, printed slip at collection builds farmer trust — the farmer can see the FAT, SNF, rate, and amount that produced their payment.
Doing this for hundreds of farmers, twice a day
By hand, this maths is slow and error-prone across a full route, morning and evening. Mobile Dairy reads FAT/SNF (or CLR), applies your rate chart automatically, prints or SMSes the slip instantly, and rolls every entry into the farmer's payment cycle — so disputes drop and settlement is faster. See the pricing plans or start a free trial below.
Related: Manual register vs digital milk collection · How to start a milk collection center in India.
