The Basics
- Simple definition: Total cost is all costs of production; average cost is total cost per unit; marginal cost is the cost of producing one more unit.
- Core idea: Three perspectives on cost – total (big picture), average (typical), marginal (next unit).
- Think of it as: Total is your entire restaurant bill; average is the bill per person; marginal is the cost of ordering one more dish.
What It Actually Means
Total cost (TC) = fixed costs (FC) + variable costs (VC). Fixed costs don’t change with output (rent, salaries); variable costs do (raw materials, energy). Average cost (AC) = TC ÷ Q. It’s U-shaped – falling with economies of scale, rising with diminishing returns. Marginal cost (MC) = change in TC from one more unit. MC crosses AC at AC’s minimum. Profit maximization occurs where MC = marginal revenue. These relationships are fundamental to firm behavior.
Example
A Pakistani bakery: rent Rs. 50,000/month (fixed), ingredients Rs. 100 per cake (variable). For 100 cakes: TC = 50,000 + 10,000 = 60,000; AC = 600; MC for 101st cake = Rs. 100 (ingredients only). If the cake price > Rs. 100, making more increases profit.
Why It Matters
Understanding these costs is essential for business decisions, pricing, output, and investment. They underlie supply curves and market analysis.
See also
Fixed Cost • Variable Cost • Cost Curves • Profit Maximization • Break-Even Point
Read more about this with MASEconomics:
Total Cost article
Differentiation in Economics
Profit Maximization