What Are FAT and SNF in Milk?
If you buy or sell milk through a dairy cooperative, collection centre, or directly from farmers, you've heard the terms FAT and SNF. Understanding these two parameters is essential because they directly determine the price per litre of milk.
FAT (Fat Content): This is the percentage of fat in the milk. Higher fat = richer, creamier milk = higher price. Buffalo milk typically has 6-8% fat, while cow milk has 3.5-5% fat.
SNF (Solids-Not-Fat): This includes proteins, lactose, minerals, and vitamins — everything solid in milk except fat. SNF typically ranges from 8-9.5%. Higher SNF indicates better nutritional quality.
Together, FAT and SNF determine the Total Solids (TS) in milk: TS = FAT + SNF. The higher the total solids, the more valuable the milk.
How Is Milk Rate Calculated?
There are several methods used across India. Let's cover the most common ones:
Method 1: FAT-Based Pricing (Most Common for Individual Doodhwalas)
This is the simplest method, used by many small dairy businesses and cooperatives:
Rate per litre = FAT% x Rate per FAT unit
Example:
- Milk FAT: 6.5%
- Rate per FAT unit (set by cooperative): ₹8.50
- Rate per litre = 6.5 x 8.50 = ₹55.25
The "rate per FAT unit" changes based on market conditions and is usually set by the cooperative or dairy. In 2026, typical rates are:
- Buffalo milk: ₹7.50-9.00 per FAT unit
- Cow milk: ₹8.00-10.00 per FAT unit (higher per unit because FAT is lower)
Method 2: Two-Axis Pricing (FAT + SNF)
Used by most large cooperatives (Amul, Karnataka Milk Federation, etc.):
Rate = (FAT% x FAT rate) + (SNF% x SNF rate)
Example:
- Milk FAT: 4.0%, SNF: 8.5%
- FAT rate: ₹7.00 per unit, SNF rate: ₹3.50 per unit
- Rate = (4.0 x 7.00) + (8.5 x 3.50) = 28.00 + 29.75 = ₹57.75 per litre
This method is fairer because it rewards both fat content and nutritional quality. A farmer with cow milk that has low fat but high SNF still gets a good price.
Method 3: TS-Based Pricing
Rate = Total Solids% x Rate per TS unit
Where Total Solids = FAT + SNF
Example:
- FAT: 6.0%, SNF: 9.0%, TS: 15.0%
- Rate per TS unit: ₹4.00
- Rate = 15.0 x 4.00 = ₹60.00 per litre
Method 4: Fixed Rate (Most Small Doodhwalas)
Many milkmen in cities simply agree on a fixed rate per litre with their customers:
- Gaay ka doodh: ₹55-70/litre (depending on city)
- Bhains ka doodh: ₹70-90/litre
No FAT/SNF testing involved. The rate is based on trust, market rates, and mutual agreement.
How to Test FAT and SNF
FAT Testing
- Gerber Method: The standard method used at collection centres. Requires a Gerber centrifuge (₹3,000-8,000), butyrometer, and sulphuric acid.
- Electronic Milk Analyser: Machines like Lactoscan or Milkotester give instant FAT, SNF, and other readings. Cost: ₹15,000-50,000 for a basic unit.
SNF Calculation
SNF can be calculated from FAT% and lactometer reading:
SNF% = (Lactometer Reading / 4) + (0.21 x FAT%) + 0.36
This formula (known as the Richmond formula variation used in Indian dairies) requires:
- A lactometer (₹200-500) to measure milk density
- The FAT% (from testing above)
Example:
- Lactometer reading: 30 (at 27°C, corrected)
- FAT%: 5.0
- SNF = (30/4) + (0.21 x 5.0) + 0.36 = 7.5 + 1.05 + 0.36 = 8.91%
Temperature Correction
Lactometer readings must be corrected for temperature. The standard temperature is 27°C (some states use 20°C):
- For every 1°C above standard: ADD 0.2 to lactometer reading
- For every 1°C below standard: SUBTRACT 0.2 from lactometer reading
FAT-Based Rate Chart (Ready Reference)
Here's a quick reference chart for buffalo milk at ₹8.00 per FAT unit:
| FAT% | Rate/Litre |
|---|---|
| 5.0 | ₹40.00 |
| 5.5 | ₹44.00 |
| 6.0 | ₹48.00 |
| 6.5 | ₹52.00 |
| 7.0 | ₹56.00 |
| 7.5 | ₹60.00 |
| 8.0 | ₹64.00 |
| 8.5 | ₹68.00 |
For cow milk at ₹9.50 per FAT unit:
| FAT% | Rate/Litre |
|---|---|
| 3.0 | ₹28.50 |
| 3.5 | ₹33.25 |
| 4.0 | ₹38.00 |
| 4.5 | ₹42.75 |
| 5.0 | ₹47.50 |
| 5.5 | ₹52.25 |
Common Issues with FAT-Based Pricing
- Milk adulteration: Adding water reduces FAT%. This is why collection centres test every batch. If you're a doodhwala buying from farmers, invest in at least a lactometer (₹200) to check density.
- Seasonal variation: FAT% naturally varies by season. Buffalo milk fat is highest in winter (7-8%) and lowest in summer (5.5-6.5%). Your purchase costs will fluctuate — plan accordingly.
- Disputes over testing: Different machines can give slightly different readings. Use calibrated equipment and maintain it regularly.
- Mixed milk complications: If you buy from multiple farmers with different FAT levels, you need to track each supplier's FAT separately and calculate weighted averages.
How Dudh Hisaab Handles FAT-Based Pricing
In Dudh Hisaab, you can set up FAT-based pricing for each supplier:
- Fixed rate mode: Set ₹X per litre — simple and straightforward
- FAT-based mode: Set the rate per FAT unit. When you record a delivery, enter the FAT%, and the app automatically calculates the rate per litre.
The app tracks daily FAT readings, calculates payments automatically, and generates reports showing average FAT, total litres, and amounts owed — for each supplier, each month.
No more manual calculation errors. No more rate disputes. Everything is recorded and transparent.
Key Takeaways
- FAT and SNF are the two main quality parameters that determine milk price
- FAT-based pricing is simplest: Rate = FAT% x Rate per unit
- Two-axis pricing (FAT + SNF) is fairest for both buyer and seller
- Invest in basic testing equipment — even a lactometer helps catch quality issues
- Use digital tools to track FAT readings and auto-calculate payments