Science-Based Target Calculator
The formula
What the science-based target tells you
Activity × factor arithmetic for science-based target: the kg CO₂e total, the offset price tag, and the scale marker (trees) that makes tonnes tangible.
Calculation: emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price. Enter your inputs and every substitution is shown below the result.
Reading the result
Compare factors against DEFRA / EPA published inventories; a factor off by 2× invalidates the whole report.
Rules of thumb: US average is ~15 t CO₂e per person per year; a typical economy car emits ~0.17 kg per km.
Limitations and best practice
Scope confusion — burning your fuel is Scope 1, your electricity is Scope 2, your supply chain is Scope 3 and usually the biggest of the three.
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
Which emission factor?
Do offsets count as reductions?
Source & methodology
DEFRA / EPA published emission factors.
Science-Based Target explained: formula, worked example and honest limits
You are here because you need a specific number, and you want to see how it was produced before you rely on it. There are plenty of pages about Science-Based Target; almost none of them show the working. This one does: the formula, every input, a fully computed example, and a sensitivity analysis calculated live from this engine’s own defaults.
A calculation like this one is worth roughly as much as a careful sentence: it forces several vague considerations into one comparable quantity. Once Science-Based Target is on the table, the argument can stop being about impressions.
People rarely disagree about arithmetic; they disagree about assumptions that were never written down. Printing the substitution and the sensitivity ranking removes that category of disagreement for Science-Based Target.
Every figure in the prose is generated by the engine rather than written beside it — the worked example resolves to science-Based Target = 2,380 kg CO₂e on the default inputs, and the sensitivity section ranks the inputs that move the result — Activity amount first, at ≈10.0 % 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.
Inside the Science-Based Target calculation: formula and every input
The engine implements a single stated model: emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price. There is no hidden coefficient and no login-gated precision — the formula printed is the formula executed, which is also what makes the result citable.
Activity amount (km, kWh, L, kg…) (example value 14,000) is a quantity rather than a category — precision here is cheap and worth having. If your source quotes a figure before and after some deduction, decide which one the formula wants and be consistent for every field.
Emission factor (kg CO₂e per unit) (example value 0) is a quantity rather than a category — precision here is cheap and worth having. Stay in one unit system top to bottom; conversion rounding is where small errors enter.
Offset price ($/t CO₂e) (example value 18) is a measured number in the unit named by the label; the formula does not convert for you. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
The default Science-Based Target calculation, written out in full
Rather than describe the calculation, here it is end to end — every substitution in order, starting from the inputs above. Starting figures: Activity amount (km, kWh, L, kg…), Emission factor (kg CO₂e per unit), Offset price ($/t CO₂e). The endpoint of that chain is 2,380 kg CO₂e of science-Based Target, sitting in the “A few tonnes — comparable to a transatlantic flight per person” band.
- kg = 14,000 × 0.1700 = 2,380
- tonnes = ÷1000 = 2.38
- Offset at $18.00/t = $42.84
Tonnes CO₂e — 2.38. If your inputs change, this is usually the first companion figure to move.
Offset cost — $42.84. If your inputs change, this is usually the first companion figure to move.
Equivalent trees to absorb/yr — 108 trees. Read next to the headline, this is the figure that shows the shape of the trade-off.
Overwrite any input above and every line of this example updates with it — the substitution is live, not a screenshot of somebody else’s numbers.
Scenario table: Science-Based Target at ±10 % and ±20 % of the key input
Single-point answers invite false confidence, so the same engine was run across a band around the input that matters most here. Each row is a full recalculation of Science-Based Target, not an interpolation.
| Activity amount setting | Science-Based Target |
|---|---|
| 80 % of the example value | 1,904 kg CO₂e |
| 90 % of the example value | 2,142 kg CO₂e |
| example inputs | 2,380 kg CO₂e |
| 110 % of the example value | 2,618 kg CO₂e |
| 120 % of the example value | 2,856 kg CO₂e |
That spread — 1,904 kg CO₂e at the low end, 2,856 kg CO₂e at the high — is what a careful read of Science-Based Target looks like: a band you can state out loud, with the reason for each edge. Reproduce it in the form above by editing Activity amount alone; the substitution steps will follow your figures exactly.
The levers behind Science-Based Target, 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 science-Based Target recomputed, so the ranking below is measured rather than asserted. It is the fastest honest answer to “what matters most in Science-Based Target?” — and it is specific to these defaults, because sensitivity moves with the starting point.
- Activity amount +10 % → Science-Based Target = 2,618 kg CO₂e · −10 % → 2,142 kg CO₂e (the science-Based Target shifts ≈10.0 %)
- Emission factor +10 % → Science-Based Target = 2,618 kg CO₂e · −10 % → 2,142 kg CO₂e (the science-Based Target shifts ≈10.0 %)
Activity amount is the dominant lever here: ten percent either way moves the result by about 10.0 %, from 2,142 kg CO₂e to 2,618 kg CO₂e. That is where a careless figure does the most damage, so check it against a source, and Emission factor is effectively tied with it (≈10.0 % for the same nudge), so verify the pair together. The rest of the inputs earn only a rounding-error of attention, and that asymmetry is the practical payoff of measuring rather than asserting.
Is your Science-Based Target good — reading the result bands
Nobody acts on a bare figure — they act on a figure with a comparison attached. The verdict attached to the default calculation — “A few tonnes — comparable to a transatlantic flight per person” — is one band on a ladder your own figure may sit somewhere else on. The sensitivity list shows how far a modest input error moves you along that ladder: for Activity amount, ±10 % covers 2,142 kg CO₂e to 2,618 kg CO₂e. The practical reading rules: read the band as a starting hypothesis, then test it: change the two dominant inputs by ten percent and see whether the verdict survives. Verdicts that survive stress are the ones worth acting on.
In Environmental & Sustainability, Science-Based Target is one instrument in an orchestra: on its own it is a number, next to Tonnes CO₂e and Offset cost it becomes a diagnosis. The tools linked above exist so the headline never has to carry that weight alone.
How people get Science-Based Target wrong
Scope confusion — burning your fuel is Scope 1, your electricity is Scope 2, your supply chain is Scope 3 and usually the biggest of the three. 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.
Reusing a Science-Based Target from last season. In Environmental & Sustainability the inputs are the thing that drifts; the formula does not.
This model has its own particular trap: Activity amount carries ≈10.0 % of the response per ten percent of error, so effort spent elsewhere is largely decorative.
A final trap is presentation: reporting Science-Based Target to more decimal places than the inputs support. The tool prints what the arithmetic gives; you should quote only what your least precise field justifies.
Science-Based Target verification checklist
- Verify each input against its original source document, not memory.
- Compare the result with one independent method or published benchmark.
- Check Activity amount before anything else: it is the measured dominant input, ≈10.0 % of Science-Based Target per ten percent.
- Recompute once with the dominant input deliberately set low, and see whether the decision changes.
- Confirm the example values are plausible for your own situation before replacing them.
- Confirm the answer against one independent method or published benchmark for Science-Based Target.
How to use the Science-Based Target 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 Science-Based Target takes a minute to learn and applies to every input above.
Step 1 — start from evidence. The inputs behind Science-Based Target are activity amount (km, kwh, l, kg…), emission factor (kg co₂e per unit), offset price ($/t co₂e). Write them down with their source next to each one; if you cannot name where a figure came from, that is the input most likely to be wrong. Estimates improve most when the worst case is written down in ink.
Step 2 — baseline before exploration. Get one defensible Science-Based Target on screen before you start nudging numbers. Without a baseline, every variation looks interesting and none of them means anything. Half of a good calculation is knowing which input you would hate to be wrong about.
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. If the answer changes your behaviour, it deserves a second run with different assumptions.
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. Say the answer out loud before you save it; if it sounds wrong, the model did not change, your understanding did.
Step 5 — write the one-line memo. “Science-Based Target = 2,380 kg CO₂e 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. When two sources disagree, it is almost never the arithmetic that differs.
Who actually uses Science-Based Target — and when
Most Carbon & Climate disagreements are arithmetic disagreements in disguise. When Science-Based Target of 2,380 kg CO₂e sits on the table with its working shown, the conversation stops being about who sounds more confident and starts being about which input is wrong. Comparisons are cheap: run the identical calculation for the alternative and look at the gap.
Used properly this is a five-minute filter that saves weeks. Compute Science-Based Target, reject what fails, and only then bring in the expensive analysis for the survivors. When in doubt, prefer the boring input: the interesting one is usually the one you misread.
There is a personal-administration use people overlook: periodic self-checking. Science-Based Target quietly drifts as life changes — rates move, bodies change, costs compound — and re-running it a few times a year catches drift while correction is still cheap. Estimates improve most when the worst case is written down in ink.
People also ask about Science-Based Target
What affects Science-Based Target the most?
Science-Based Target is driven above all by Activity amount. Perturbing only that field by ten percent either way produced 2,618 kg CO₂e against the 2,380 kg CO₂e baseline — a ≈10.0 % response, while Emission factor manages ≈10.0 %.
Do emission factor and activity amount matter equally?
Effectively. Measured on this engine they land at ≈10.0 % and ≈10.0 % for the same ten-percent nudge, so the honest advice is to get both right; chasing precision in only one of them buys almost nothing.
What is a typical Science-Based Target?
On the worked example above Science-Based Target comes out at 2,380 kg CO₂e. 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 Science-Based Target by hand?
emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price is the entire method. Work the inputs in that order — kg = 14,000 × 0.1700 = 2,380 — and you will reach 2,380 kg CO₂e on the default figures, the same number this tool prints.
What happens to Science-Based Target if activity amount changes by 10 %?
Try it in the form above and the printed substitution will follow you; the pre-computed answer for the defaults is 2,142 kg CO₂e to 2,618 kg CO₂e across the ten-percent probe, i.e. ≈10.0 % sensitivity on the science-Based Target.
Is the Science-Based Target result of 2,380 kg CO₂e good or bad?
Neither, on its own — the label “A few tonnes — comparable to a transatlantic flight per person” is the band this figure falls in for the example inputs, and your own inputs will place you elsewhere on the same ladder. Judge the number against your history and your alternatives, and remember that a ten-percent error in Activity amount alone moves it by ≈10.0 %.
How do I calculate Science-Based Target manually?
Write down the inputs, then follow the printed steps in order — emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price. A spreadsheet replicates it with two or three cells. The manual route is worth doing once to build intuition; after that the calculator saves time and eliminates transcription slips.
Is Science-Based Target accurate?
The arithmetic is exact: emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price 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 2,380 kg CO₂e result as the correct answer to the question you typed — and check the assumptions section before acting on it.
Which emission factor?
Match the source: grid electricity differs by country, transport by vehicle class. Public inventories (DEFRA, EPA) publish annually.
Do offsets count as reductions?
No — offsets pay someone else; the hierarchy remains reduce, replace, then offset the residue.
Can this tool see the numbers I type?
It cannot. There is no submission step: the calculation happens in your browser and the result disappears when you close the page. Treat the fields above as a scratchpad rather than a form.
Glossary for Science-Based Target
- Tonnes CO₂e
- 2.38 in the default Science-Based Target calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Offset cost
- $42.84 in the default Science-Based Target calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Equivalent trees to absorb/yr
- 108 trees on the example inputs — a companion figure printed beside the headline of Science-Based Target so that no result is read in isolation.
- Science-Based Target
- The primary output of this tool: 2,380 kg CO₂e for the default inputs, computed exactly from emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price.
- Worked example
- Every substitution in order, from the example inputs to 2,380 kg CO₂e — the audit trail for the headline figure.
- Verdict band
- The interpretation attached to a result (“A few tonnes — comparable to a transatlantic flight per person” on these inputs), which turns a bare number into a position on a scale.
- Sensitivity (±10 %)
- How far the Science-Based Target moves when a single input is nudged ten percent either way; the ranked list on this page is computed live from this engine.
The provenance of this Science-Based Target calculation
The model is published arithmetic implemented exactly as written: emissions = activity × factor; tonnes = kg ÷ 1000; offset cost = tonnes × price. Source of record: DEFRA / EPA published emission factors. Where a professional version of this calculation differs, it differs in inputs and jurisdiction-specific coefficients, not in the algebra — which is why re-checking your inputs beats hunting for a second calculator.
Nothing here replaces a qualified professional, and nothing here is approximate either — the arithmetic is exact, and the honesty is in the inputs you supply. The design constraint was set by usefulness rather than by comfort: an estimate you can interrogate beats an answer you have to trust.
Turning this Science-Based Target into a decision
Re-run the calculation with your own figures, stress the two most sensitive inputs by ±10 %, and only then act on the result.
The audience here is people who need one trustworthy number before their next decision. Everything you need to defend the result — formula, substitution, sensitivity, source — is printed above, so the only remaining variable is the honesty of your inputs.