GDP, GNP, NDP and NNP: Factor Cost and Market Price Made Easy

You recognise every abbreviation on the page. Then a question starts with GNP at factor cost, asks for NDP at market price, and suddenly you cannot remember which amount to add.

The difficulty is usually not the arithmetic. It is trying to remember a separate formula for every possible journey.

Try a smaller task: compare the name you have with the name you need. Has gross changed to net? Has national changed to domestic? Has factor cost changed to market price? Each change has its own adjustment.

Once you can spot those three changes, even an unfamiliar conversion becomes manageable.

Read the Name Before You Read the Numbers

A complete aggregate tells you three things:

Part of the name	Question it answers	Two possibilities
Capital consumption	Has depreciation been deducted?	Gross or net
Income boundary	Are we measuring domestic production or income accruing to normal residents?	Domestic or national
Valuation	Which tax and subsidy treatment is being used?	Market price or factor cost

For example, NNP at FC means Net National Product at Factor Cost. Every word matters. The first N means net; the second means national.

The four main abbreviations are:

• GDP: Gross Domestic Product.
• NDP: Net Domestic Product.
• GNP: Gross National Product.
• NNP: Net National Product.

Each can appear at market price, written MP, or factor cost, written FC, in textbook conversion questions. That gives eight familiar combinations.

National income, in this textbook framework, means NNP at FC. Domestic income means NDP at FC. These labels and the basic conversion identities are set out in NCERT’s National Income Accounting chapter.

The Three Adjustments You Actually Need

1. Gross to Net: Subtract Depreciation

Gross measures have not deducted consumption of fixed capital. Net measures have.

Net = Gross - Depreciation
Gross = Net + Depreciation

Depreciation here means the value of fixed capital consumed through normal wear, deterioration and obsolescence during the period. It is also called consumption of fixed capital, or CFC. It does not mean a fall in the exchange rate. The BEA’s explanation of national accounting concepts explains this economic depreciation measure.

Imagine a small economy produces final output worth Rs. 900 crore, while its machinery and other fixed assets lose Rs. 70 crore of value through normal use and ageing. Its NDP at the same valuation is:

900 - 70 = Rs. 830 crore

We do not subtract the entire purchase price of every machine. We subtract the capital consumed during the year.

2. Domestic to National: Add NFIA

Domestic production and income accruing to residents do not have identical boundaries. Some income generated domestically accrues to nonresidents; residents can also earn factor income abroad.

Net factor income from abroad, or NFIA, is:

NFIA = Factor income from abroad
       - Factor income paid abroad

National = Domestic + NFIA
Domestic = National - NFIA

Think of wages earned across borders by people who remain residents, and investment income receivable from or payable to nonresidents. The key is economic residence, not simply nationality or passport. The OECD’s explanation of gross national income describes this residence-based adjustment and its income components.

Suppose factor income from abroad is Rs. 85 crore and factor income paid abroad is Rs. 125 crore:

NFIA = 85 - 125 = -40 crore

With GDP at MP of Rs. 900 crore:

GNP at MP = 900 + (-40)
          = Rs. 860 crore

National is lower than domestic in this example. The word “national” does not guarantee a larger number.

3. Market Price to Factor Cost: Subtract Net Indirect Taxes

In the usual school conversion framework:

Net indirect taxes (NIT)
= Indirect taxes - Subsidies

FC = MP - NIT
MP = FC + NIT

Write out the bracket if the question gives taxes and subsidies separately:

FC = MP - Indirect taxes + Subsidies

A tax included in market valuation is not factor remuneration. A production subsidy supports factor earnings without requiring an equal payment from the buyer. This is why the two adjustments have opposite signs.

For an aggregate at MP of Rs. 900 crore, indirect taxes of Rs. 110 crore and subsidies of Rs. 30 crore:

NIT = 110 - 30 = 80 crore
Aggregate at FC = 900 - 80 = Rs. 820 crore

This conversion uses indirect taxes and relevant subsidies, not personal income tax. A more detailed valuation framework separates product taxes from other production taxes; we will deal with that distinction below. The Indian Economic Service explanation of valuation bases is useful for understanding that bridge.

Your Conversion Ladder

Here is one reliable route from GDP at MP to national income:

GDP at MP
   - Depreciation
= NDP at MP
   + NFIA
= NNP at MP
   - Net indirect taxes
= NNP at FC
= National income

The combined formula is:

National income = GDP at MP - Depreciation + NFIA - NIT

You can make the adjustments in another order. For instance, changing MP to FC first gives GDP at FC; subtracting depreciation then gives NDP at FC; adding NFIA gives NNP at FC.

What matters is that each required change happens once.

All Eight Aggregates From One Starting Point

Let A = GDP at MP, D = depreciation, F = NFIA, and T = NIT. The table is a reference you can reconstruct, rather than eight separate formulas to memorise.

Aggregate	Starting from A
GDP at MP	A
GDP at FC	A - T
NDP at MP	A - D
NDP at FC	A - D - T
GNP at MP	A + F
GNP at FC	A + F - T
NNP at MP	A + F - D
NNP at FC	A + F - D - T

Cover the right column and try to rebuild it. For NDP at FC, for example, you need two changes from GDP at MP: gross to net and MP to FC. The domestic boundary stays the same, so NFIA is irrelevant.

Worked Example 1: Calculate All Eight Aggregates

The following data describe an imaginary economy for one year. All amounts are in Rs. crore.

Item	Amount
GDP at MP	12,000
Depreciation	800
Factor income from abroad	450
Factor income paid abroad	650
Indirect taxes	1,100
Subsidies	300

First calculate the two net adjustments:

NFIA = 450 - 650 = -200
NIT = 1,100 - 300 = 800

Now build the answer:

Aggregate	Calculation	Rs. crore
GDP at MP	Given	12,000
GDP at FC	12,000 - 800	11,200
NDP at MP	12,000 - 800	11,200
NDP at FC	12,000 - 800 - 800	10,400
GNP at MP	12,000 + (-200)	11,800
GNP at FC	12,000 - 200 - 800	11,000
NNP at MP	12,000 - 200 - 800	11,000
NNP at FC	12,000 - 200 - 800 - 800	10,200

National income is Rs. 10,200 crore. Domestic income is Rs. 10,400 crore. Their difference is NFIA, which is negative Rs. 200 crore.

Two pairs happen to be equal: GDP at FC equals NDP at MP, and GNP at FC equals NNP at MP. That happens because depreciation and NIT both equal Rs. 800 crore here. It is a numerical coincidence, not a general identity.

A useful reverse check is:

GDP at MP
= NNP at FC + Depreciation - NFIA + NIT
= 10,200 + 800 - (-200) + 800
= 12,000 crore

Getting back to the starting figure is reassuring, especially when NFIA is negative.

Worked Example 2: Reverse the Journey

Given:

• National income: Rs. 7,600 crore.
• Depreciation: Rs. 500 crore.
• NFIA: negative Rs. 120 crore.
• Indirect taxes: Rs. 900 crore.
• Subsidies: Rs. 250 crore.

Find GDP at MP.

Start by translating the given label: national income is NNP at FC.

NIT = 900 - 250 = 650 crore

NNP at FC = 7,600
GNP at FC = 7,600 + 500 = 8,100
GDP at FC = 8,100 - (-120) = 8,220
GDP at MP = 8,220 + 650 = 8,870

GDP at MP is Rs. 8,870 crore.

Why did subtracting NFIA increase the answer? Because national income already reflects a net factor-income outflow. Moving back to the domestic boundary reverses that adjustment.

Do not mentally rewrite “minus NFIA” as “minus 120”. The value of NFIA is -120, so the expression is -(-120).

Worked Example 3: Do Not Adjust a Word That Has Not Changed

GNP at FC is Rs. 6,200 crore. Depreciation is Rs. 400 crore, NFIA is Rs. 150 crore, and NIT is Rs. 500 crore. Find NDP at MP.

Compare the two names:

1. Gross becomes net: subtract 400.
2. National becomes domestic: subtract 150.
3. FC becomes MP: add 500.

NDP at MP = 6,200 - 400 - 150 + 500
          = Rs. 6,150 crore

Now suppose the question instead asks for NNP at FC from the same starting point. Only gross changes to net:

NNP at FC = 6,200 - 400
          = Rs. 5,800 crore

The other given figures are not needed for that second question. A question can supply more information than the requested conversion requires.

Worked Example 4: Find Missing Depreciation

GDP at MP is Rs. 15,000 crore, national income is Rs. 13,250 crore, NFIA is negative Rs. 250 crore, and NIT is Rs. 900 crore. Find depreciation.

Write the relationship before rearranging:

NI = GDP at MP - D + NFIA - NIT
13,250 = 15,000 - D + (-250) - 900
13,250 = 13,850 - D
D = 600 crore

Depreciation is Rs. 600 crore.

You can also rearrange first:

D = GDP at MP + NFIA - NIT - NI
  = 15,000 - 250 - 900 - 13,250
  = 600 crore

Check by rebuilding the national-income answer: 15,000 - 600 - 250 - 900 = 13,250.

If a similar question gives a negative answer for ordinary depreciation, recheck the signs and data. A minus sign attached to NFIA is easy to lose when moving it across an equation.

Worked Example 5: When Subsidies Exceed Indirect Taxes

NDP at MP is Rs. 3,000 crore. Indirect taxes are Rs. 90 crore and subsidies are Rs. 140 crore. NFIA is Rs. 60 crore. Find national income.

NIT = 90 - 140 = -50 crore

NDP at FC = 3,000 - (-50)
          = 3,050 crore

NNP at FC = 3,050 + 60
          = Rs. 3,110 crore

Here, the factor-cost figure exceeds the corresponding market-price figure. There is no contradiction: subtracting negative NIT increases the amount.

Also notice that we did not deduct depreciation. The starting aggregate was already net.

Worked Example 6: Start With Expenditure Data

Sometimes GDP is not given directly. Suppose an imaginary economy has the following figures, all in Rs. crore:

Item	Amount
Private final consumption expenditure	4,200
Government final consumption expenditure	1,100
Gross domestic capital formation	1,300
Exports	700
Imports	850
Depreciation	350
NFIA	-90
NIT	410

First obtain GDP at MP using final expenditure:

GDP at MP = C + I + G + (X - M)
          = 4,200 + 1,300 + 1,100 + (700 - 850)
          = 6,450 crore

This expenditure identity is described in the BEA’s GDP definitions. Here, investment is gross domestic capital formation, including inventory change; government final consumption does not include transfer payments.

Now apply the ladder:

NI = 6,450 - 350 + (-90) - 410
   = Rs. 5,600 crore

Net exports of -150 and NFIA of -90 are separate adjustments. Exports and imports concern goods and services; NFIA concerns factor incomes across borders. Subtracting imports does not eliminate the need for NFIA.

If your difficulty is deciding which production or expenditure belongs in GDP to begin with, work through our guide to double counting and the value-added method before attempting the conversion.

Factor Cost Is Not the Same as Basic Prices

You may see GVA at basic prices in an economic report. Do not automatically substitute it for GDP at FC.

The fuller bridge is:

GVA at FC
+ Other production taxes
- Other production subsidies
= GVA at basic prices

Economy-wide GVA at basic prices
+ Product taxes
- Product subsidies
= GDP at MP

In this distinction, other production taxes relate to carrying on production rather than the quantity or value of a specific product. Product taxes attach to products. The Ministry of Statistics and Programme Implementation’s national accounts methodology uses the GVA-at-basic-prices plus net-product-taxes bridge for GDP.

For practice, suppose economy-wide GVA at basic prices is Rs. 5,000 crore, product taxes are Rs. 600 crore and product subsidies are Rs. 100 crore:

GDP at MP = 5,000 + 600 - 100
          = Rs. 5,500 crore

If other production taxes are Rs. 80 crore and other production subsidies are Rs. 20 crore:

GVA at FC = 5,000 - 80 + 20
          = Rs. 4,940 crore

The full factor-cost-to-market-price difference is 560: net product taxes of 500 plus net other production taxes of 60.

Three Conceptual Traps Behind Wrong Answers

A Foreign-Owned Factory Does Not Disappear From Domestic Production

Suppose a factory operating within an economy’s domestic territory has nonresident owners. Its domestic value added still contributes to GDP. When moving to a national measure, account for the relevant income accruing to nonresidents through NFIA.

Do not remove the factory’s whole output. That would also remove domestic contributions such as resident employees’ earnings.

A Family Gift From Abroad Is Not Automatically NFIA

Consider a person who is a resident of another economy sending a gift to family at home. That transfer is different from wages or investment income earned by a resident from abroad.

National income and national disposable income are not identical: current transfers enter the latter distinction. The IMF’s national accounts manual separates primary incomes from the subsequent redistribution through transfers.

Read the nature of the receipt and the stated residence of the person. “Money came from overseas” is not enough to classify it as factor income.

Gross Does Not Mean All Sales Added Together

Gross means before deducting depreciation. It does not give permission to count intermediate goods again alongside final goods. Avoiding double counting and deducting depreciation solve different problems.

A Quick Method for Any Conversion Question

Use this five-line working pattern:

1. Given aggregate: write its complete name, including MP or FC.
2. Required aggregate: write its complete name beside it.
3. Net adjustments: calculate NFIA and NIT where necessary.
4. Conversion: change only the parts of the name that differ.
5. Answer: state the resulting aggregate and units, then reverse-check if time permits.

For example, a student writes:

Given: NNP at MP
Required: NDP at FC

Net remains net: no depreciation adjustment.
National to domestic: subtract NFIA.
MP to FC: subtract NIT.

NDP at FC = NNP at MP - NFIA - NIT

That is a complete plan before a single number enters the calculation.

Practice: Try the Route Before Looking at the Answer

All figures below are in Rs. crore. Each question is independent.

1. A Straight Conversion

GDP at MP = 8,000, depreciation = 600, NFIA = 100, indirect taxes = 700 and subsidies = 200. Find national income.

Answer: NIT = 500. NI = 8,000 - 600 + 100 - 500 = 7,000.

2. Starting From Domestic Income

Domestic income = 4,500, depreciation = 300, NFIA = -80 and NIT = 400. Find GNP at MP.

Answer: Domestic income is NDP at FC. GNP at MP = 4,500 + 300 + (-80) + 400 = 5,120.

3. Find NFIA

GNP at MP = 9,400 and GDP at MP = 9,650. Find NFIA and interpret its sign.

Answer: NFIA = 9,400 - 9,650 = -250. Factor income paid abroad exceeds factor income from abroad by 250.

4. A Net-to-Net Question

NNP at MP = 5,700, NFIA = -150 and NIT = 450. Depreciation is 280. Find domestic income.

Answer: NDP at FC = 5,700 - (-150) - 450 = 5,400. Depreciation is not needed.

5. Find the Subsidy

GDP at MP = 6,800, GDP at FC = 6,300 and indirect taxes = 650. Find subsidies.

Answer: NIT = 6,800 - 6,300 = 500. Subsidies = 650 - 500 = 150.

6. Reverse a Negative NFIA Adjustment

NNP at FC = 10,000, depreciation = 700, NFIA = -300 and NIT = 900. Find GDP at MP.

Answer: GDP at MP = 10,000 + 700 - (-300) + 900 = 11,900.

7. Work From Basic Prices

Total GVA at basic prices = 7,200, product taxes = 900, product subsidies = 250, depreciation = 400 and NFIA = 50. Find NNP at MP.

Answer: GDP at MP = 7,200 + 900 - 250 = 7,850. NNP at MP = 7,850 - 400 + 50 = 7,500.

8. Spot the Wrong Adjustment

A student calculates NNP at FC from NDP at FC by adding NFIA, deducting depreciation and deducting NIT. Which adjustments are unnecessary?

Answer: Deducting depreciation and NIT are both unnecessary. Only domestic changes to national. The correct conversion is NNP at FC = NDP at FC + NFIA.

Frequently Asked Questions

What is the easiest way to remember GDP, GNP, NDP and NNP conversions?

Compare three features: gross or net, domestic or national, and MP or FC. Apply only the adjustments needed to change the starting name into the requested name. Reconstructing the route is safer than recalling a long formula from memory.

Which aggregate is called national income?

In the traditional school framework used here, national income is NNP at factor cost. Domestic income is NDP at factor cost. The difference between them is NFIA.

Can GNP be smaller than GDP?

Yes, at the same valuation, when NFIA is negative. For example, GDP of 1,000 and NFIA of -70 give GNP of 930.

Is depreciation deducted when converting GDP to GNP?

No. Both aggregates are gross. At the same valuation, add NFIA only. Depreciation is needed when changing gross to net, such as GDP to NDP.

Why do we add subsidies when converting market price to factor cost?

The conversion subtracts net indirect taxes, defined as indirect taxes minus subsidies. Expanding the bracket gives MP minus indirect taxes plus subsidies.

Can factor cost be higher than market price?

Yes, when the relevant subsidies exceed indirect taxes. NIT is then negative, and subtracting it raises the factor-cost figure above the corresponding market-price figure.

Are net exports and NFIA the same?

No. Net exports equal exports minus imports of goods and services. NFIA is the net cross-border factor-income adjustment. In Worked Example 6, both appear and serve different purposes.

Does national income include every citizen’s earnings anywhere in the world?

Do not use citizenship alone. National accounting uses economic residence. Read the question’s residence assumptions before deciding whether an overseas earning belongs in factor income from abroad.

Are basic prices and factor cost interchangeable?

No. Other production taxes less other production subsidies separate them. Net product taxes then connect economy-wide GVA at basic prices to GDP at market prices.

Does changing market price to factor cost give real GDP?

No. That adjustment changes the treatment of taxes and subsidies. Real GDP concerns valuation using constant prices rather than current prices. Keep the price-year question separate from the MP-versus-FC question.