Skip to content
KhetiTools
EN हिं
Fertilizer Calculators

SSP (Single Super Phosphate) Calculator

Calculate Single Super Phosphate needed from your P₂O₅ dose, and the sulphur it supplies.

Enter your details

%
kg

Please note: This calculator provides a mathematical estimate based on the values entered. Recommended agricultural application rates can vary by crop, soil, product formulation, location and official agricultural guidance. Check the product label and local agricultural recommendations before application.

Single Super Phosphate (SSP) supplies 16% P2O5 along with about 11% sulphur and some calcium. Enter your phosphorus dose to see how much SSP to buy and how much sulphur you'll be giving the crop.

About the SSP Calculator

SSP is a lower-strength phosphorus fertilizer than DAP – 16% P2O5 against 46% – so you need nearly three times the weight for the same phosphorus. What makes it worth the extra bags is what else it carries: roughly 11% sulphur and a useful amount of calcium, with no nitrogen at all.

That combination suits oilseeds such as groundnut, mustard and soybean, which need sulphur for oil and protein formation, and pulses, which fix their own nitrogen and don't benefit from the extra N in DAP. Sulphur deficiency has become common in many Indian soils, so SSP is also a practical way to correct it.

This calculator gives you the SSP quantity, the number of bags and the sulphur supplied. To compare SSP and DAP side by side, try both options in the NPK Calculator.

How to use the SSP Calculator

  1. 1 Enter your field area and choose the unit.
  2. 2 Enter the P2O5 dose. Pick kg per acre or kg per hectare to match your recommendation.
  3. 3 Keep 16% for standard powdered or granulated SSP.
  4. 4 Press Calculate to see SSP, bags and sulphur supplied.

The formula we use

SSP (kg) = Total P₂O₅ ÷ 16 × 100
Sulphur supplied (kg) = SSP × 11 ÷ 100
Bags = SSP ÷ 50

Shortcut: SSP = P2O5 × 6.25. One 50 kg bag gives 8 kg P2O5 and about 5.5 kg sulphur.

Worked example

Groundnut on 1 hectare, with a recommendation of 40 kg P2O5 per hectare.

  1. SSP = 40 ÷ 16 × 100 = 250 kg, which is 5 bags.
  2. Sulphur supplied = 250 × 11% = 27.5 kg S – enough to meet the sulphur need of most oilseed crops.

The same phosphorus from DAP would be only 87 kg, but you would get no sulphur and an extra 15.7 kg of nitrogen.

Things to keep in mind

  • More bags to handle. Because SSP is weaker, transport and labour for application are higher. Factor that into your cost.
  • Apply at sowing. Like DAP, SSP should be placed in the soil at or before sowing.
  • Nitrogen must come from elsewhere. SSP has no N, so the full nitrogen requirement comes from urea or other sources.
  • Grades vary. Some fortified SSP products (with boron or zinc) are sold. Check the bag and adjust the percentage if needed.

Frequently asked questions

Is SSP better than DAP?

Neither is universally better. DAP is more concentrated and cheaper per kg of P2O5 to transport. SSP adds sulphur and calcium and no nitrogen, which suits oilseeds, pulses and sulphur-deficient soils.

How much SSP equals one bag of DAP?

One 50 kg bag of DAP supplies 23 kg P2O5. You would need 23 ÷ 0.16 = 143.75 kg, or almost 3 bags, of SSP for the same phosphorus.

How much sulphur does SSP contain?

Standard SSP contains about 11% sulphur, so a 50 kg bag supplies roughly 5.5 kg of sulphur.

Can SSP be used for paddy and wheat?

Yes. SSP works for any crop that needs phosphorus. Just remember to supply all the nitrogen through urea or other sources.

Last updated . Spotted a mistake or need a unit we don't support? Tell us.