Calculate marginal utility, total utility, utility per money unit, and the point where extra consumption stops adding value.
e.g. pizza slice, coffee, app feature.
Utility data
Enter the satisfaction each additional unit gives you (0–100 works well). Total utility is summed automatically.
Editable utility and price rows
Unit
Label
Utility
Price
Remove
1
2
3
4
5
6
Diagnosis
Classic diminishing marginal utility
Your data shows classic diminishing marginal utility. Total utility rises to a peak of 275 at unit 5, but marginal utility falls with each additional pizza slice. Unit 6 has negative marginal utility, so total utility declines after unit 5.
Total utility
270
across 6 pizza slices
Average utility
45
per unit consumed
Latest marginal utility
-5
unit 6
Latest utility / $
-1.67
best: unit 1
Diminishing starts
Unit 2
MU first falls here
Satiation (MU = 0)
None
not reached
Negative utility
Unit 6
TU falls past this unit
Suggested stop
Unit 5
max TU = 275
Total utility curve
Total utilityKey points
Your data shows classic diminishing marginal utility. Total utility rises to a peak of 275 at unit 5, but marginal utility falls with each additional pizza slice. Unit 6 has negative marginal utility, so total utility declines after unit 5.
Marginal utility & utility per $
Marginal utilityUtility / $Key points
Your result
What the result means
Diminishing marginal utility begins around unit 2: total utility keeps rising, but each extra pizza slice adds less satisfaction than the one before.
Unit 1 gives the highest satisfaction per $ (utility per dollar 33.33).
Marginal utility becomes negative at unit 6, so consuming beyond unit 5 reduces total satisfaction.
Suggested stopping point: unit 5. Unit 6 has negative marginal utility, so unit 5 is the practical stopping point.
Total utility can keep rising while marginal utility falls — each extra unit still adds satisfaction, just less than before. Utility scores are subjective and entered by you, so treat the result as a learning and decision-support tool.
Utility schedule
Per-unit total utility, marginal utility, cumulative cost, utility per $ and status
Unit
Label
Total utility
Marginal utility
Avg utility
Price
Utility / $
Status
1
Slice 1
100
100
100
$3.00
33.33
Highest satisfaction
2
Slice 2
180
80
90
$3.00
26.67
Diminishing but useful
3
Slice 3
235
55
78.33
$3.00
18.33
Diminishing but useful
4
Slice 4
265
30
66.25
$3.00
10
Diminishing but useful
5
Slice 5
275
10
55
$3.00
3.33
Low value
6
Slice 6
270
-5
45
$3.00
-1.67
Overconsumption
Showing 5 of 6 rows.
Compare two items or scenarios
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Scenario B editable utility and price
Unit
B utility
B price
1
2
3
4
5
Total utility
A: 270 · B: 170
Total cost
A: 18 · B: 20
Max total utility
A: 275 · B: 190
Avg utility per $
A: 15 · B: 8.5
Pizza slice gives higher total utility, and Pizza slice gives better average utility per dollar. If your goal is maximum satisfaction, choose the higher-total-utility option; if your goal is value for money, choose the higher utility-per-dollar option.
Multi-good budget allocation
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Compare marginal utility per $ across two or more goods. The calculator allocates a budget by always choosing the good whose next unit gives the highest utility per $ — the equimarginal principle in action.
This is a structured educational model. Utility scores are only comparable across goods if you use a consistent scale.
Good 1
e.g. 80, 60, 40, 20
Good 2
e.g. 80, 60, 40, 20
Utility scores are comparable across goods only if they share the same scale — treat this as an educational model, not a precise purchase recommendation.
Total utility
270
from allocated budget
Total cost
$28.00
$2.00 remaining
Suggested purchase order by marginal utility per $
Step
Good
Unit
MU
Price
MU / $
Running total utility
1
Good A
1
80
$5.00
16
80
2
Good A
2
60
$5.00
12
140
3
Good B
1
70
$8.00
8.75
210
4
Good A
3
40
$5.00
8
250
5
Good A
4
20
$5.00
4
270
Purchase order follows the equimarginal rule: each step buys the next unit with the highest utility per $, in sequence. Based on your utility scores.
Marginal rate of substitution (MRS) helper
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MRS = MUX ÷ MUY. Consumer equilibrium requires MUX / PX = MUY / PY. Enter the marginal utility and price for each good at a given quantity.
Good X
The extra satisfaction from one more unit of this good.
Price per unit of this good.
Good Y
The extra satisfaction from one more unit of this good.
Price per unit of this good.
MRS (MUx ÷ MUy)
1.33
Price ratio (Px ÷ Py)
1.67
MU / $ — Good X
16
MU / $ — Good Y
20
Better value: Good Y
Good Y gives more satisfaction per unit of money (20 vs 16). Shifting spending toward Good Y would raise total utility, according to this educational model.
MRS–price-ratio gap: 0.33. When the gap is small, the allocation is close to the consumer equilibrium condition.
Based on your entered marginal utility scores. This is an educational model — real indifference curves, income effects, and budget constraints involve more factors.
Save & export — generated from your current inputs
The Excel workbook uses live formulas — edit the utility scores or prices inside Excel or Google Sheets and the analysis recalculates.
What this tool shows
Compare goods using the equimarginal rule, check the marginal rate of substitution, and build a utility schedule from a table or mathematical function.
Total utility, marginal utility, average utility, and utility per money unit for every unit
Automatic detection of where diminishing marginal utility begins
Satiation point (MU = 0), first negative-utility unit, and suggested stopping point
Multi-good budget allocation using the equimarginal rule
Marginal rate of substitution (MRS) helper and consumer equilibrium check
Mathematical function presets: square-root, log, quadratic, and linear utility
Two-scenario comparison, total-utility and MU curves with key markers
7-tab formula-driven Excel workbook and CSV export
Formula-backed economics calculator with utility curves, diminishing-utility diagnosis, and a downloadable XLSX workbook.
Updated 14 June 2026 · Runs entirely in your browser
Marginal utilityThe extra satisfaction or value gained from consuming one more unit of something. is the extra satisfaction from one more unit of a good: MU = change in total utility ÷ change in quantity. Enter a utility score and price for each unit and this calculator builds total utility, marginal utility, and utility per dollar, then marks where diminishing marginal utility begins and where extra units stop being worth it.
Where total utility peaks at 275 and the sixth slice drags it back to 270
Score six pizza slices at 100, 80, 55, 30, 10, −5 and the table returns total utility as a running sum — 100, 180, 235, 265, 275, 270 — with marginal utility equal to those per-unit scores. Marginal utility is the extra satisfaction from one more unit, MU = ΔTU ÷ ΔQ, the difference between two consecutive rows. Total utility is the satisfaction from every unit consumed so far, not just the latest one. If you already know marginal utility at each quantity, total utility at any quantity is the sum of every marginal utility up to that point; if instead you enter total utility at each quantity, this calculator derives marginal utility by taking the difference between consecutive rows.
The decision the table hands you sits in the sign of MU, not its size. While MU is positive, total utility keeps climbing; diminishing marginal utility begins at the second slice, where MU falls from 100 to 80. That is the law at work: as you consume more of one good, holding everything else equal, the marginal utility of each additional unit eventually declines. The satiation point is slice five — MU has run down to zero and total utility peaks at 275. Slice six carries a marginal utility of −5, so total utility falls to 270; consuming past satiation has a real cost, not merely a zero return.
The average-utility column (TU ÷ quantity) turns over as soon as marginal utility drops below the running average, which in this table is slice two as well. That downward-sloping MU curve — plotted here from your own values, with the satiation point marked and the zero crossing visible — is one reason demand curves slope down: each extra unit is worth less to you, so you will only take it at a lower price. Total utility and marginal utility move in opposite directions only once MU turns negative; before that, total utility rises the whole way while marginal utility falls.
From ΔTU ÷ ΔQ to MU₁ ÷ P₁ = MU₂ ÷ P₂
Four expressions generate every column below. In Function Presets mode the same four run against a textbook utility function — U(x) = √x, log, quadratic, or linear — instead of typed rows, computing total utility, marginal utility, and utility per dollar at each quantity directly from the function, so you can hold a curve you assumed against a table you actually scored.
Total utility
TU = Σ marginal utilities
Running sum of satisfaction (or entered directly in total mode).
Marginal utility
MU = ΔTotal Utility ÷ ΔQuantity
Extra satisfaction from one more unit. MU = 0 is the satiation point.
Utility per dollar
Utility/$ = MU ÷ Price
Value for money (N/A when price is 0).
Consumer equilibrium
MU₁ ÷ P₁ = MU₂ ÷ P₂ = …
Maximise utility on a fixed budget.
When the good with the higher MU is the wrong home for your next dollar
Raw marginal utility ranks units inside one good; it cannot rank spending across goods, because the goods carry different prices. Utility per dollar = MU ÷ price is the column that can, and this calculator computes it for every row you enter. It measures satisfaction gained per unit of money spent, which is what you actually compare across goods when the budget is limited: of two goods at the same price, the one with the higher marginal utility per dollar is the better use of the next dollar — and a good with the lower marginal utility but the lower price can win outright.
Apply the rule repeatedly and it terminates in the equimarginal principle: keep moving the next dollar to whichever good returns the most utility per dollar, and stop when the ratio is level everywhere you spend — MU₁/P₁ = MU₂/P₂ = …, consumer equilibrium. That equality is the test the multi-good module runs when it allocates a budget across the goods and prices you list. Change one price and re-run: the two-scenario comparison shows the reordering directly, because a price rise cuts utility per dollar for that good while its marginal utility never moved.
The same column drives the suggested stopping point. Set a minimum utility per dollar and this calculator returns the last unit at or above it; leave it unset and the stop falls back to the unit before the first negative MU — slice five in the pizza table. A value-for-money floor can halt you well short of satiation.
When MRS equals the price ratio, there is nothing left to trade
The marginal rate of substitution is that same equilibrium seen from the trading side: MRS = MUX ÷ MUY, the units of good Y you would give up for one more unit of good X while total satisfaction stays unchanged. The MRS helper builds it from the utility scores you have already entered.
Set MRS against the price ratio and it becomes a stopping rule. MUX/PX = MUY/PY is the same statement as MRS = PX ÷ PY, so once what you are willing to trade matches what the market charges to trade, no further reshuffling of the basket raises total utility. Above that ratio, hold more X; below it, more Y.
Your scores are ordinal, so two goods compare only on one scale
The arithmetic here is exact; the inputs are opinions. That gap is the real limitation behind every number this tool returns, and it is why any comparison across goods needs one shared scale to mean anything.
Methodology
This calculator computes total utility, marginal utility, and utility per dollar from the scores and prices you enter, and identifies diminishing utility by comparing marginal utility across units. The on-page engine and the Excel workbook formulas are validated against hand-computed cases and an Excel-compatible formula engine on every change. Results reflect your own subjective scores.
Utility is subjective and ordinal — the scores represent your own ranking, not a physical measurement in real units.
Cross-good utility comparisons (multi-good module, MRS helper) are only meaningful when all scores use a consistent scale.
The multi-good allocation follows a greedy equimarginal rule, which is an approximation — it does not account for income effects, substitute goods not listed, or diminishing MU that develops mid-allocation.
Preferences change with mood, context, time, and habit — a single table is a snapshot, not a model of general behaviour.
No live consumer data, empirical demand estimates, or professional economic, behavioural, or financial advice.
One distinction this tool does not make for you: diminishing marginal utility is about consumption — what an extra unit is worth to whoever consumes it — while diminishing returns is about production, the extra output an extra input buys. They share the word "diminishing" but describe different processes. For the production side, see the diminishing returns calculator.
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There is no dedicated marginal-utility guide yet. The formula section above covers the equimarginal principle and MRS in full.
Sources and methodology
The utility scores on this page are your own subjective rankings, not a measured quantity, and nothing here is fetched. Diminishing marginal utility, the equimarginal principle and the marginal rate of substitution are standard microeconomic models taught in the references below - no government, regulator or standards body sets a utility curve or a satiation point. The spending statistic is included only as a real-world anchor for how households divide a budget. Links open in a new tab.
This tool is for educational and decision-support purposes only. Utility is subjective and ordinal — the scores you enter represent your own ranking of satisfaction, not a physical measurement. The calculator does not replace professional economic, behavioural, or financial advice, and real choices also depend on budget, alternatives, context, and changing preferences. Educational explanation follows standard consumer-choice microeconomics as set out in the sources listed on this page.
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