Personal Carbon Budget Analyzer

Projected Annual Emissions

{{ total_t.toFixed(2) }} tCO₂e

Budget {{ budget_t.toFixed(2) }} t · Under by {{ Math.abs(gap_t).toFixed(2) }} t Over by {{ gap_t.toFixed(2) }} t

Preset: {{ budgetPresetLabel }} Grid {{ grid_intensity_kg_per_kwh }} kg/kWh {{ car_type==='ice'?'Car (ICE)':'Car (EV)' }} Offsets {{ formatNumber(offsets_kg,0) }} kg {{ gap_kg<=0?'On track':'Needs cuts' }}

Preset:

Budget: / year

Offsets purchased: kg / year

Electricity: kWh / month

Grid intensity: kg / kWh

Natural gas: therm / month

Gas factor: kg / therm

Heating oil: L / month

Oil factor: kg / L

Vehicle:

Car miles: mi / year

Economy: mpg

Fuel: kg / gal

EV miles: mi / year

EV consumption: kWh / 100 mi

Car occupancy:

people

Flights (km): km / year

Flight factor:

kg / km

Non‑CO₂ multiplier:

{{ Number(rf_multiplier || 0).toFixed(1) }}×

Public transit (km): km / year

Transit factor: kg / km

Diet preset:

Diet emissions: kg / day

Other: kg / year

Category	kg / year	% of total
{{ r.label }}	{{ formatNumber(r.kg,0) }}	{{ r.share.toFixed(1) }}%
Total	{{ formatNumber(total_kg,0) }}	100%
Budget (kg/yr)	{{ formatNumber(budget_kg,0) }}	{{ budget_kg>0 ? ((total_kg/budget_kg)*100).toFixed(1) : '—' }}%
{{ gap_kg<=0 ? 'Under by' : 'Over by' }}	{{ formatNumber(Math.abs(gap_kg),0) }}	—

Tags: Education , Productivity

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Personal carbon budgets are annual allowances of greenhouse gas emissions for one person, grounded in everyday activities across energy, travel, food, and purchases. They help turn climate goals into a clear yearly limit you can track and adjust over time.

Emissions are estimated from the energy you use at home, the distance you travel by road, rail, and air, and the footprint of diet and other spending. You set a target for the year and see how closely your projected total lines up with that number.

Enter monthly electricity and heating use, choose the type of vehicle or skip it, add annual flight and transit distance, and pick a diet pattern or daily value. The result shows a projected yearly total and whether you are under or over a chosen budget with the gap quantified.

A simple example helps. A household using three hundred kilowatt hours each month with natural gas, two thousand kilometres of flights in a year, and an average diet will land near six tonnes in total, so a three tonne budget will show an overrun that invites a plan to reduce the biggest sources first.

Treat the estimate as a guide. Values are based on average factors and simple inputs, so repeat measurements, keep units consistent, and look for steady trends rather than single points.

If you carpool, share miles fairly by occupancy, and include offsets only when they are actually purchased and retired.

Technical Details:

The analyzer estimates carbon dioxide equivalent (CO₂e) from household energy, transport activity, diet, and other purchases. Quantities are monthly energy use in kilowatt hours, therms, and litres, plus annual distance by mode and daily diet footprint. All figures roll up to kilograms per year and convert to tonnes for summary context.

Total emissions are computed by multiplying each activity by its emission factor, summing categories, and subtracting any offsets. The result is compared to a user‑set budget to show a gap. Categories are electricity, natural gas, heating oil, personal car travel, flights, public transit, diet, and other known sources.

Results are interpreted against a simple boundary at zero gap. A non‑positive gap indicates you are on track for the year, while a positive gap signals the need to cut emissions or raise offsets. The cumulative chart assumes even accrual through the year for both emissions and budget to help visualize drift early.

Comparisons are most meaningful when you keep units consistent across runs and update factors when you have better local values, such as a grid intensity specific to your region. Diet values are rough averages and capture only food‑related emissions, not full supply chains.

\begin{matrix} E_gross & = & E_elec + E_gas + E_oil + E_car + E_flights + E_transit + E_diet + E_misc \\ E_total & = & max (0, E_gross - Offsets_kg) \\ B_kg & = & B_value \times S \\ where S = 1000 if unit is tonnes, otherwise 1 \\ Gap_kg & = E_total - B_kg \end{matrix}

\begin{matrix} E_elec & = & 12 \times kWh_mo \times f_grid \\ E_gas & = & 12 \times therm_mo \times f_gas \\ E_oil & = & 12 \times L_mo \times f_oil \\ E_car (ICE) & = & (mi_yr \div occ \div mpg) \times f_fuel \\ E_car (EV) & = & (mi_yr \div occ \times kWh_100 \div 100) \times f_grid \\ E_flights & = & km_yr \times f_flight \times m_rf \\ E_transit & = & km_yr \times f_transit \\ E_diet & = & d_day \times 365 \\ E_misc & = & m_kg \end{matrix}

Symbols and units
Symbol	Meaning	Unit/Datatype	Source
E_elec	Electricity emissions	kg/year	Derived
E_gas	Natural gas emissions	kg/year	Derived
E_oil	Heating oil emissions	kg/year	Derived
E_car	Personal car emissions	kg/year	Derived
E_flights	Flight emissions	kg/year	Derived
E_transit	Public transit emissions	kg/year	Derived
E_diet	Diet‑related emissions	kg/year	Derived
E_misc	Other known emissions	kg/year	Input
E_gross	Sum before offsets	kg/year	Derived
E_total	Net after offsets	kg/year	Derived
B_kg	Budget as kilograms	kg/year	Derived
Gap_kg	Over‑ or under‑budget	kg/year	Derived
f_grid	Grid intensity factor	kg/kWh	Input
f_gas	Gas emission factor	kg/therm	Input
f_oil	Oil emission factor	kg/L	Input
f_fuel	Fuel factor (ICE)	kg/gal	Input
kWh₁₀₀	EV consumption	kWh/100 mi	Input
m_rf	Non CO₂ multiplier	× (1–3)	Input

Worked example

Defaults: electricity 300 kWh/month, grid factor 0.40 kg/kWh; natural gas 25 therm/month at 5.3 kg/therm; flights 2000 km at 0.15 kg/km with multiplier 1.0; transit 1000 km at 0.05 kg/km; diet 5.0 kg/day; other 500 kg/year; no offsets; budget 3.0 t/year.

\begin{matrix} E_elec & = & 12 \times 300 \times 0.40 = 1440 & kg \\ E_gas & = & 12 \times 25 \times 5.3 = 1590 & kg \\ E_flights & = & 2000 \times 0.15 \times 1.0 = 300 & kg \\ E_transit & = & 1000 \times 0.05 = 50 & kg \\ E_diet & = & 5.0 \times 365 = 1825 & kg \\ E_misc & = & 500 & kg \\ E_gross & = & 5705 & kg \\ E_total & = & 5705 & kg \\ B_kg & = & 3.0 \times 1000 = 3000 & kg \\ Gap_kg & = & 5705 - 3000 = 2705 & kg \end{matrix}

Interpretation: 2705 kg over budget for the year → “Needs cuts.”

Interpretation bands
Threshold band	Lower bound	Upper bound	Interpretation	Action cue
On track	−∞	0 kg	Projected total is at or below budget.	Maintain progress or bank slack.
Needs cuts	> 0 kg	+∞	Projected total exceeds budget.	Target the largest categories first.

Key parameters and defaults
Parameter	Meaning	Unit/Datatype	Default	Notes
Budget	Annual target	kg or t/year	3 t	Presets 2–5 t; custom supported.
Offsets	Purchased offsets	kg/year	0	Subtracted from gross.
f_grid	Electricity factor	kg/kWh	0.40	Presets 0.20, 0.40, 0.60; custom allowed.
f_gas	Natural gas factor	kg/therm	5.3	Editable.
f_oil	Heating oil factor	kg/L	2.68	Editable.
f_fuel (gasoline)	ICE fuel factor	kg/gal	8.89	Diesel default 10.16.
kWh₁₀₀	EV use per 100 mi	kWh/100 mi	30	Used with f_grid.
m_rf	Non CO₂ multiplier	×	1.0	Range 1–3 via slider.

Units, precision & rounding

Table kilograms are rounded to the nearest integer; category shares show one decimal place.
Summary tonnes display two decimals; cumulative monthly series round to two decimals.
Distances mix miles for car use and kilometres for flights and transit; conversions are not automatic.

Validation & bounds (selected)

Input constraints
Field	Type	Min	Max	Step/Pattern	Error text
Budget value	number	0	—	0.01	—
Offsets	number	0	—	1	—
Electricity (kWh/month)	number	0	—	1	—
Grid intensity (kg/kWh)	number	0	—	0.01	—
Natural gas (therm/month)	number	0	—	1	—
Gas factor (kg/therm)	number	0	—	0.1	—
Heating oil (L/month)	number	0	—	1	—
Oil factor (kg/L)	number	0	—	0.01	—
Car miles (ICE)	number	0	—	1	—
MPG (ICE)	number	1	—	0.1	—
Fuel factor (kg/gal)	number	0	—	0.01	—
EV miles	number	0	—	1	—
EV kWh/100 mi	number	1	—	0.1	—
Car occupancy	number	1	—	0.1	—
Flights (km/year)	number	0	—	1	—
Flight factor (kg/km)	number	0	—	0.01	—
Non CO₂ multiplier	range	1	3	0.1	—
Transit (km/year)	number	0	—	1	—
Transit factor (kg/km)	number	0	—	0.01	—
Diet (kg/day)	number	0	—	0.1	Disabled unless custom.
Other (kg/year)	number	0	—	1	—

I/O formats

Input and output formats
Input	Accepted families	Output	Encoding/precision	Rounding
Numbers	Integers and decimals	Table & charts	kg and t	As listed above
—	—	CSV / JSON / DOCX	Strings via export	Same as display

Networking & storage

All calculations run in the browser; no data is sent to a server.
A charting layer is retrieved from a public CDN to render visuals.
Clipboard and file exports operate locally on your device.

Assumptions & limitations

Heads‑up Flight uplift uses a simple multiplier rather than a route model.
Budget accrues evenly by month; seasonal swings are not modeled.
Grid intensity is a single factor; time‑of‑use variation is not captured.
Diet value is a rough daily average, not a dietary assessment.
Carpooling is handled by occupancy only; empty return trips are not modeled.
“Other” is a catch‑all and should be used carefully to avoid double counting.
Offsets are treated as a subtraction with no quality screening.
Embodied emissions of vehicles or buildings are not included.

Edge cases & error sources

Negative inputs are rejected by field constraints.
Division by zero in MPG is prevented by a minimum of 1.
Occupancy cannot fall below 1; shared trips below one person are invalid.
Very large values may reduce readability due to rounding to integers in kg.
Mixing miles and kilometres without care skews totals.
Rounding at two decimals in tonnes may hide small month‑to‑month changes.
Custom factors entered with the wrong unit will distort results.
Clipboard operations can fail if permissions are denied.
Charts may not render if the CDN is blocked or offline.
Locale number formatting can display different separators than expected.

Step‑by‑Step Guide:

Personal annual emissions and the budget gap are estimated from a few activity inputs.

Set a budget preset or enter a custom target t or kg per year.
Enter monthly electricity and heating values; adjust grid and fuel factors if you know better numbers.
Choose vehicle type and add miles with MPG for ICE or consumption for EV; set occupancy for shared trips.
Add annual flight kilometres and, if desired, a non CO₂ multiplier simple uplift.
Enter public transit kilometres, pick a diet preset or daily value, and add any other known sources.
Optionally copy or download the breakdown as CSV or JSON, or export a DOCX summary.

Example: With the defaults above the total is about 5.705 tCO₂e/year against a 3.000 t budget, indicating cuts are needed.

Tip: Update factors once a year and keep a dated JSON export for comparisons.

FAQ:

Is my data stored?

No. Calculations happen in your browser. The only network request is to fetch the charting layer, and nothing you enter is transmitted or saved server‑side.

Clipboard and file exports stay on your device.

How accurate is the estimate?

It reflects the inputs and factors you provide. It is best for planning and tracking progress rather than auditing. Update factors when you have better local values.

Use consistent units and repeat measurements.

Which units are supported?

Electricity is in kWh/month, gas in therm/month, oil in L/month, car travel in miles/year, flights and transit in km/year. Budgets are in kilograms or tonnes per year.

Can I use it offline?

Yes after the page and charting layer are cached. If the layer is unavailable, charts may not render but the table and totals still work.

What about cost or licensing?

The package does not declare a license in its metadata. Treat it as educational and verify licensing with the author before redistribution or commercial use.

How do I pick a grid intensity?

Use the average preset to start. If you know a regional value, switch to custom and enter that figure to improve accuracy.

What does a borderline gap mean?

A gap near zero suggests you are roughly on track. Small swings can be rounding noise. Recheck assumptions and focus attention on the largest categories.

Troubleshooting:

Charts do not appear — the charting layer may be blocked; try a connection that allows CDN access.
Copy fails — allow clipboard permissions or use the download option instead.
Numbers look wrong — confirm units and factor values, especially grid and fuel factors.
Diet field disabled — choose the custom diet preset to edit daily kg.
EV shows high values — check kWh per 100 mi and ensure occupancy is set correctly.
CSV opens garbled — import with UTF‑8 and set the delimiter to comma.

Blocking issue: If all numbers become zero, reload the page to re‑initialize state and re‑enter values.

Advanced Tips:

Tip Track a few what‑if scenarios by saving separate JSON files named with date and change notes.

Tip Use occupancy to share car miles across travellers for fair personal accounting.

Tip Lower the grid factor if you buy verified renewable electricity and can justify the adjustment.

Tip Set the non CO₂ multiplier above 1 only when you intentionally account for high‑altitude effects.

Tip Revisit diet values a few times a year if your eating pattern changes.

Tip When over budget, aim first at the highest‑share rows in the breakdown for the biggest impact.

Glossary:

tCO₂e: Tonnes of carbon dioxide equivalent, a combined greenhouse gas metric.
kgCO₂e: Kilograms of carbon dioxide equivalent, the base unit here.
Grid intensity: Emissions per kilowatt hour of electricity consumed.
MPG: Miles per gallon, a measure of fuel economy for ICE vehicles.
Non CO₂ multiplier: Simple uplift to include high altitude and related effects.
Budget gap: Difference between projected net emissions and the annual target.