Calculating the Revenue Impact of Additional Sales
The Marginal Revenue Calculator determines how much additional revenue each new unit generates. Enter your current and projected revenue and quantity figures to find MR, compare it against average revenue, and assess whether expanding production is financially sound.
The Insights panel shows whether MR indicates pricing power or diminishing returns, flags price dilution, and identifies your profit threshold — the maximum marginal cost where additional units remain profitable.
The Marginal Revenue Formula
MR = (Revenue_new - Revenue_current) / (Quantity_new - Quantity_current)
= Change in Total Revenue / Change in Quantity
MR compared to average revenue reveals your pricing dynamics:
- MR > Average: Each new unit is more valuable — pricing power or premium positioning
- MR = Average: Perfectly efficient scaling — constant returns
- MR < Average: Diminishing returns — new units dilute per-unit revenue
- MR < 0: Additional units reduce total revenue — overproduction
Worked Example: 1,000 to 1,100 Units
A manufacturer sells 1,000 units for $50,000 total revenue. They project selling 1,100 units for $52,000.
- Change in Revenue: $52,000 - $50,000 = $2,000
- Change in Quantity: 1,100 - 1,000 = 100 units
- Marginal Revenue: $2,000 / 100 = $20.00 per unit
- Avg Revenue (Before): $50,000 / 1,000 = $50.00 per unit
- Avg Revenue (After): $52,000 / 1,100 = $47.27 per unit
Analysis: MR of $20 is 60% below the current average of $50. Average revenue drops $2.73/unit (-5.5%), indicating price dilution. The 100 additional units add only $2,000 in revenue — $20 each vs. the $50 average for existing units. If marginal cost exceeds $20, those additional units lose money.
MR Across Different Scenarios
| Scenario | Revenue Change | Qty Change | MR | Signal |
|---|---|---|---|---|
| Strong pricing power | $50K → $56K | 1,000 → 1,100 | $60 | MR > Avg ($50) — expand |
| Moderate returns | $50K → $52K | 1,000 → 1,100 | $20 | MR < Avg — diminishing returns |
| Break-even expansion | $50K → $50K | 1,000 → 1,100 | $0 | No revenue gain from more units |
| Revenue destruction | $50K → $48K | 1,000 → 1,100 | -$20 | Reduce production immediately |
The key decision: compare MR against marginal cost. MR of $20 is profitable if MC < $20, unprofitable if MC > $20.
Marginal Revenue in Practice
E-commerce/FMCG: MR typically $5-$20/unit with tight margins and high volume. Watch for MR declining as you saturate your addressable market or increase ad spend with diminishing click-through rates.
SaaS subscriptions: MR per new subscriber often $50-$500/month with near-zero marginal costs, making MR almost entirely profit. Focus on customer acquisition cost vs. MR.
Manufacturing: MR ranges $100-$10,000+ per unit for specialized equipment. Compare MR against material, labor, and tooling costs for each incremental batch.
