Skip to content
KhetiTools
EN हिं
Fertilizer Calculators

Urea Calculator

Find out how much urea to buy for your field from the nitrogen dose, in kilograms and 45 kg bags.

Enter your details

The nitrogen dose from your recommendation – not the urea quantity.

Standard neem-coated urea is 46% N.

%
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.

Urea is 46% nitrogen, so the amount of urea you need is always more than the nitrogen written on your recommendation. Enter the field size and the nitrogen dose, and this calculator gives you the exact quantity of urea and the number of 45 kg bags to buy.

About the Urea Calculator

Urea Calculator

Urea is the most widely used fertilizer in India and the cheapest source of nitrogen per kilogram. It is also the one most often over-applied. Part of the reason is simple confusion between nitrogen and urea: if a recommendation says 40 kg N per acre, some farmers apply 40 kg of urea (too little) and others throw in "one bag extra to be safe" (too much).

The fix is a one-line calculation. Because urea contains 46 kg of nitrogen in every 100 kg of product, you divide the nitrogen you need by 46 and multiply by 100. This calculator does that for your full field, converts between acres and hectares if needed, and tells you how many 45 kg bags that comes to.

It is useful for:

  • Working out urea for a single top-dressing when phosphorus and potash are already applied.

  • Checking a dealer's suggestion against your Soil Health Card dose.

  • Calculating split doses – just enter the nitrogen for that split.

If your recommendation includes phosphorus as well, use the NPK Calculator instead. It accounts for the nitrogen supplied by DAP, which lowers the urea you need.

How to use the Urea Calculator

  1. 1 Enter the area you are fertilizing and select the unit.
  2. 2 Enter the nitrogen dose per acre or per hectare. Use the nitrogen figure from your recommendation – for split doses, enter only the nitrogen for this split.
  3. 3 Leave nitrogen content at 46% unless your product label says otherwise.
  4. 4 Press Calculate to see the kilograms of urea and the number of 45 kg bags.

The formula we use

Total N needed (kg) = N dose per acre × area in acres
Urea (kg) = Total N ÷ 46 × 100
Bags = Urea (kg) ÷ 45

A quick mental shortcut: urea ≈ nitrogen × 2.17. So 50 kg N needs about 109 kg urea.

Worked example

You want to top-dress 3 acres of paddy with 40 kg nitrogen per acre.

  1. Total nitrogen = 40 × 3 = 120 kg N.

  2. Urea = 120 ÷ 46 × 100 = 260.9 kg.

  3. Bags = 260.9 ÷ 45 = 5.8, so buy 6 bags and keep the small balance for the next split.

That works out to about 87 kg of urea per acre.

Things to keep in mind

  • Split the dose. Most crops use nitrogen best when urea is applied in two or three splits rather than all at once. Heavy single doses are easily lost to leaching and volatilisation.

  • Apply to moist soil. Broadcasting urea on dry soil in hot weather, or on standing water in paddy, loses a large share of the nitrogen as ammonia gas.

  • 45 kg bags. Urea in India has been sold in 45 kg bags since 2018. If you still have older 50 kg bags, change the bag weight.

  • Nano urea and liquids are applied at different rates by spraying; this calculator is for granular urea only.

  • More is not better. Excess nitrogen makes crops lodge, attracts sucking pests and delays maturity.

Frequently asked questions

How much urea should I put per acre?

It depends on the crop, soil and season. The calculator converts the nitrogen dose into urea; for the dose itself, follow your Soil Health Card or your state agriculture university's recommendation for your crop.

How much nitrogen is in one bag of urea?

A 45 kg bag of urea at 46% N contains 20.7 kg of nitrogen.

How do I convert nitrogen to urea?

Divide the nitrogen by 0.46 (or multiply by about 2.17). For example, 60 kg N ÷ 0.46 = 130.4 kg urea.

Why is my urea figure lower in the NPK calculator?

Because the NPK calculator subtracts the nitrogen already supplied by DAP. This calculator assumes all the nitrogen comes from urea.

Can I mix urea with DAP and MOP before applying?

Urea mixes reasonably with MOP, but mixtures with DAP can become sticky in humid weather. Mix just before application and apply the same day. Check local advice for your crop.

Is neem-coated urea different?

Neem-coated urea still contains 46% nitrogen. The thin neem coating slows nitrogen release slightly and discourages diversion for non-farm uses. You calculate it exactly the same way.

Guides that use this calculator

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