Carbon-Adjusted Return Calculator
The formula
What the carbon-adjusted return tells you
Exactly what carbon-adjusted return earned: total return, the annualised CAGR that makes it comparable, and the split between price gain and income.
Calculation: Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1. Enter your inputs and every substitution is shown below the result.
Reading the result
Compare with the boring alternative over the same window — the verdict bands anchor to long-run market returns; income-heavy gains are usually steadier than price-only ones.
Rules of thumb: Long-run real equity return sits near 6–7 % nominal CAGR plus inflation; bonds run 2–4 points lower.
Limitations and best practice
Ignoring the timing of income (reinvested vs spent) can overstate a CAGR by a few tenths; dividends spent as cash belong outside the ending value.
This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Frequently asked questions
Why does CAGR differ from average yearly return?
Are taxes included?
Source & methodology
Time-weighted return arithmetic per CFA Institute conventions.
Carbon-Adjusted Return explained: formula, worked example and honest limits
Capital decisions deserve better than a gut feeling — this page gives you the arithmetic to defend one. Carbon-Adjusted Return is the kind of number people argue about from memory. This page ends that argument with arithmetic you can watch happen: enter your figures, get Total return in real time, and see every substitution printed below.
In Environmental & Sustainability the same quantity is often quoted under two or three different conventions. The formula printed above fixes one convention and applies it consistently, which is what makes results from this page comparable with each other.
Sustainability numbers carry a double burden: they must be right, and they must be honest. Carbon-Adjusted Return does the arithmetic (Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1); the responsibility for realistic inputs — Buy price / invested ($), Sell price / value now ($) — belongs to the person reporting. A -27.73% figure survives scrutiny only when both halves hold.
Every figure in the prose is generated by the engine rather than written beside it — the worked example resolves to total return = -27.73% on the default inputs, and the sensitivity section ranks the inputs that move the result — Buy price / invested first, at ≈29.0 % of the headline for a ten-percent error either way in that input. Read the sections in order and you will be able to reproduce every figure by hand.
The Carbon-Adjusted Return formula, explained
One formula, published in full: Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1. Anything you can read, you can reproduce in a spreadsheet, and that reproducibility is the whole point of printing it rather than hiding it behind a button.
Buy price / invested ($) (example value 18,500) is a quantity rather than a category — precision here is cheap and worth having. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
Sell price / value now ($) (example value 12,500) is a measured number in the unit named by the label; the formula does not convert for you. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
Holding period (years) (example value 8) is a quantity rather than a category — precision here is cheap and worth having. Be precise about the boundary (exact date, start of month); time inputs decide the exponent in most formulas.
Income received over the hold ($) (example value 870) is a numeric input whose unit is fixed by the label; a wrong unit is a wrong answer wearing a plausible disguise. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
A fully worked Carbon-Adjusted Return example
Abstract formulas are hard to trust, so here is the complete substitution using the default inputs, written the way an examiner would want it. Starting figures: Buy price / invested ($), Sell price / value now ($), Holding period (years), Income received over the hold ($). The endpoint of that chain is -27.73% of total return, sitting in the “Negative over the hold — the annualised figure below sizes the bleed” band.
- Ending value incl. income = $12,500.00 + $870.00 = $13,370.00
- Total return = (13,370.00 − 18,500.00) ÷ 18,500.00 = -27.73 %
- CAGR = (13,370.00 ÷ 18,500.00)^(1/8.0) − 1 = -3.98 % a year
Annualised (CAGR) — -3.98%. Compare it against the main result of -27.73% before drawing conclusions.
Net profit — $-5,130.00. Read next to the headline, this is the figure that shows the shape of the trade-off.
Value multiple — 0.72 ×. Compare it against the main result of -27.73% before drawing conclusions.
Income share of gain — 0.0%. This is the number experienced users quote when the headline alone would mislead.
Re-running with your own figures is instant; re-running by hand once is the best way to know the tool is telling you the truth.
How far Carbon-Adjusted Return can reasonably move
Read this table as the practical error bar on the headline figure. It answers the question people actually have after seeing a single number: how wrong could this be if the main input is off by ten or twenty percent?
| Buy price / invested setting | Total return |
|---|---|
| 80 % of the example value | -9.66% |
| 90 % of the example value | -19.70% |
| example inputs | -27.73% |
| 110 % of the example value | -34.30% |
| 120 % of the example value | -39.77% |
Across 5 settings of Buy price / invested, the result spans -39.77% to -9.66%. A decision that only works at one row of this table is a decision waiting for an input to move. Reproduce it in the form above by editing Buy price / invested alone; the substitution steps will follow your figures exactly.
The levers behind Carbon-Adjusted Return, ranked by effect
Generic advice says “it depends on your inputs”; this section says exactly how much. Each field was perturbed by ±10 % in isolation and the total return recomputed, so the ranking below is measured rather than asserted. It is the fastest honest answer to “what matters most in Carbon-Adjusted Return?” — and it is specific to these defaults, because sensitivity moves with the starting point.
- Buy price / invested +10 % → Carbon-Adjusted Return = -34.30% · −10 % → -19.70% (the total return shifts ≈29.0 %)
- Sell price / value now +10 % → Carbon-Adjusted Return = -20.97% · −10 % → -34.49% (the total return shifts ≈24.4 %)
- Nudge Income received over the hold by ±10 % and Carbon-Adjusted Return lands between -28.20% and -27.26% (sensitivity ≈1.7 %)
Buy price / invested is the dominant lever here: ten percent either way moves the result by about 29.0 %, from -34.30% to -19.70%. Measure that input from a document rather than from memory, and treat Sell price / value now as the second priority (≈24.4 % per ten percent). The rest of the inputs earn only a rounding-error of attention, and that asymmetry is the practical payoff of measuring rather than asserting.
What a Carbon-Adjusted Return of -27.73% means in practice
The value above only becomes useful the moment you know what it is being measured against. The verdict attached to the default calculation — “Negative over the hold — the annualised figure below sizes the bleed” — is one band on a ladder your own figure may sit somewhere else on. How much of that band is luck? On Buy price / invested alone ten percent either way covers -34.30% to -19.70%. The practical reading rules: compare against your own history before comparing against other people; treat band boundaries as zones, not walls — one point on the wrong side of a threshold rarely changes a real outcome; and when a companion output contradicts the headline, believe the pair.
Set Carbon-Adjusted Return beside its neighbours and it usually plays a specific role: this figure establishes the size of something, and the neighbouring tools establish whether that size is acceptable. Skipping the first step makes the second one arbitrary.
How people get Carbon-Adjusted Return wrong
Ignoring the timing of income (reinvested vs spent) can overstate a CAGR by a few tenths; dividends spent as cash belong outside the ending value. This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Chasing precision in Sell price / value now ($) while Buy price / invested ($) is still a guess. The sensitivity ranking above shows exactly where the accuracy budget should go.
One mistake is specific to this engine: assuming every input matters equally. The computation above shows Buy price / invested dominating — a careful figure there beats false precision everywhere else.
Another is comparing across contexts: a Carbon-Adjusted Return computed with one set of conventions should never be lined up against a figure computed with another. Check the inputs behind both before ranking them.
Carbon-Adjusted Return verification checklist
- State, in one sentence, which convention each rate, unit or period in the form is using.
- Record the date and the inputs alongside the number so future-you knows what was assumed.
- Check Buy price / invested before anything else: it is the measured dominant input, ≈29.0 % of Carbon-Adjusted Return per ten percent.
- Confirm the example values are plausible for your own situation before replacing them.
- Recompute once with the dominant input deliberately set low, and see whether the decision changes.
- Confirm the answer against one independent method or published benchmark for Carbon-Adjusted Return.
How to use the Carbon-Adjusted Return tool properly
Using a calculator well sounds trivial, but the difference between a decision-grade figure and a throwaway one lives entirely in the routine. The routine for Carbon-Adjusted Return takes a minute to learn and applies to every input above.
Step 1 — one document, one pass. Open the statement, label or record that holds buy price / invested ($), sell price / value now ($), holding period (years), income received over the hold ($) and transcribe straight into the form. Transcription from a single source removes the mismatch errors that appear when figures are assembled from three different places. Say the answer out loud before you save it; if it sounds wrong, the model did not change, your understanding did.
Step 2 — compute the version you would not be embarrassed by. If a stranger audited your inputs, which set would you hand over? Enter that set, read the result, and treat everything else as upside. The input you reach for first is usually the one you measured longest ago.
Step 3 — change one input at a time. Nudge a single field by ten percent, watch the headline and its companions move, then undo it. Two or three fields will dominate — the sensitivity table above already ranks them for this engine. Re-running a number costs seconds; retracting a decision costs considerably more.
Step 4 — stress before you commit. A decision that survives a ten-percent squeeze on its two biggest inputs needs no luck to be sound. One that does not survive is a decision about hope, not about arithmetic. The fastest sanity test is to guess the answer first and see how far the calculation disagrees.
Step 5 — write the one-line memo. “Total return = -27.73% on this date, from these inputs.” That line is the entire deliverable; everything else on this page is how you earned the right to write it. Rounding early is the quietest way to introduce a permanent error.
Who actually uses Carbon-Adjusted Return — and when
Environmental & Sustainability arguments end at arithmetic or they do not end. Carbon-Adjusted Return is the arithmetic: -27.73% on the example inputs, reproducible by anyone who types the same numbers. A calculation you cannot explain to somebody else is a calculation you cannot defend.
Professionals in Carbon & Climate use this style of calculation as a screening filter before spending real money or effort: a quick Carbon-Adjusted Return check eliminates weak options in minutes, and the survivors earn the deeper, slower analysis. Precision is a promise you make about your data; make sure your inputs can keep it.
Re-running this page costs nothing and catches the slow drifts that never announce themselves. In Environmental & Sustainability the expensive mistakes are rarely sudden; they are small changes in Buy price / invested ($) that nobody recalculated for a year. Estimates improve most when the worst case is written down in ink.
People also ask about Carbon-Adjusted Return
What affects Carbon-Adjusted Return the most?
Carbon-Adjusted Return is driven above all by Buy price / invested. Perturbing only that field by ten percent either way produced -34.30% against the -27.73% baseline — a ≈29.0 % response, while Sell price / value now manages ≈24.4 %.
Which matters more: sell price / value now or buy price / invested?
For Carbon-Adjusted Return, Buy price / invested wins the head-to-head (≈29.0 % against ≈24.4 % per ten-percent change). Knowing which input dominates is the difference between careful work and merely slow work.
What is a typical Carbon-Adjusted Return?
On the worked example above Carbon-Adjusted Return comes out at -27.73%. Treat that as one point on a distribution rather than a norm: the bands, the companion outputs and the sensitivity ranking tell you how wide the plausible range really is.
How do I calculate Carbon-Adjusted Return by hand?
Use the stated model — Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1 — and substitute in the order the tool prints (it starts from Ending value incl. income = $12,500.00 + $870.00 = $13,370.00). On the example inputs the hand route lands on -27.73%, exactly what the calculator shows. A spreadsheet reproduces it in two or three cells; doing it once by hand is what makes the automated answer trustworthy.
What happens to Carbon-Adjusted Return if buy price / invested changes by 10 %?
Try it in the form above and the printed substitution will follow you; the pre-computed answer for the defaults is -34.30% to -19.70% across the ten-percent probe, i.e. ≈29.0 % sensitivity on the total return.
Is the Carbon-Adjusted Return result of -27.73% good or bad?
Good and bad are comparisons, so the honest test is three questions: where does your own Carbon-Adjusted Return sit against the -27.73% reference above, how far would a plausible input error move it (≈29.0 % per ten percent on Buy price / invested), and what does the alternative option compute to?
Is Carbon-Adjusted Return accurate?
The arithmetic is exact: Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1 is evaluated with full floating-point precision and every substitution is printed in the worked example. What limits accuracy is input quality and the model’s assumptions, so treat the -27.73% result as the correct answer to the question you typed — and check the assumptions section before acting on it.
How often should I check Carbon-Adjusted Return?
Whenever an input changes by more than a few percent, and otherwise on the rhythm of your decisions — before a purchase, a review, a renewal. Carbon-Adjusted Return is a snapshot, not a subscription; stale snapshots are the most common silent error in Environmental & Sustainability planning.
Why does CAGR differ from average yearly return?
CAGR compounds — it is the single steady rate that turns the start into the end, while arithmetic averages flatter volatile paths.
Are taxes included?
No, this is the pre-tax picture; subtract tax drag on gains and income before comparing with a tax-sheltered alternative.
Does this Carbon-Adjusted Return tool store my numbers?
No. The entire calculation runs in your browser session; nothing entered above is transmitted or saved, which is the correct behaviour for sensitive Environmental & Sustainability figures and the reason you can re-run this page as often as you like.
What the labels on this page mean
- Annualised (CAGR)
- -3.98% for the Carbon-Adjusted Return worked case; it sits next to the main result because it carries context the headline leaves out.
- Net profit
- $-5,130.00 in the default Carbon-Adjusted Return calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Value multiple
- 0.72 × in the default Carbon-Adjusted Return calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Total return
- The primary output of this tool: -27.73% for the default inputs, computed exactly from Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1.
- Worked example
- The step-by-step substitution printed above, so the arithmetic can be re-derived by hand or in a spreadsheet.
- Verdict band
- The plain-language label — here “Negative over the hold — the annualised figure below sizes the bleed” — mapping the computed figure onto experience-based ranges for Environmental & Sustainability.
- Sensitivity (±10 %)
- How far the Carbon-Adjusted Return moves when a single input is nudged ten percent either way; the ranked list on this page is computed live from this engine.
Where the Carbon-Adjusted Return model comes from
The model is published arithmetic implemented exactly as written: Total return = (sell + income − buy) ÷ buy; CAGR = ((sell + income) ÷ buy)^(1/years) − 1. Source of record: Time-weighted return arithmetic per CFA Institute conventions. Specialist software layers extra coefficients on top of the same algebra; none are hidden here, and that transparency is what makes a disagreement traceable to a specific input instead of a black box.
This page is an estimation aid, not professional advice. The design rule is simple: two people entering identical figures must get identical answers. Nothing is smoothed, weighted or adjusted behind the scenes; where judgement enters, this page says so and names the input responsible.
Next steps after the calculation
Run the pessimistic case before the optimistic one; an opportunity that survives the pessimistic inputs is the only kind worth pursuing.
This page was written for investors and founders comparing opportunities on equal terms, and the promise is that nothing above required trust. Bookmark the tool, re-run it whenever an input moves by more than a few percent, and keep the date with the number.