# How do I calculate my carbon footprint if some months of electricity bills are missing?

Canonical: https://senseible.earth/answers/missing-electricity-bills-carbon-footprint

First try to recover the real figure: download duplicate bills from your discom or use the meter readings on the next bill. Only then estimate the gap, from the average of the months either side or the same month last year scaled to production, and label it as an estimate in your report.

## Recover the actual units before you estimate

- Duplicate bills: many discoms let you download past bills from their consumer portal or issue a copy at the sub-division office.
- Meter readings: the first bill after the gap prints a previous reading. Subtract the closing reading of the last bill you hold and you have the actual kWh for the whole gap, even if you cannot split it by month.
- Payment records: bank or accounts entries prove a bill existed for that month and give the amount, which helps you check an estimate, but rupees are not kWh.

## Which estimate to use for a gap

Pick one method, apply it to every gap in the year, and keep the working. The GHG Protocol Corporate Standard does not prescribe a gap method; it asks that estimates be transparent, consistent and documented as part of managing inventory quality.

1. If the gap is one or two months and production was steady, use the average of the months on either side.
2. If your load is seasonal (cold storage, air conditioning, crop processing), use the same month last year, scaled by this year's production or operating days.
3. If you know the total kWh across the gap from meter readings, split it across the missing months in proportion to production instead of guessing the total.

## How to disclose estimated months

State which months were estimated, the method, and the share of total Scope 2 that comes from estimates. A buyer or auditor will accept a small, clearly labelled estimate far more readily than a full year that silently includes filled-in months. If estimates are a large share of the year, say so and fix the record keeping before the next year.

## Mistakes that inflate or hide the gap

- Copying a bill twice to cover a missing month. The duplicate is easy to spot and undermines the rest of the record.
- Using billed demand (kVA) or kVAh in place of kWh. The grid factor applies to kWh.
- Treating a provisional or average bill from the discom as an actual reading. Check for a note such as 'average' or 'meter not read' and treat that month as an estimate too.

## Worked example: two missing months in a year

- Ten bills held: 450,000 kWh in total; January 40,000 kWh, April 44,000 kWh; February and March missing
- Estimate for each missing month: (40,000 + 44,000) / 2 = 42,000 kWh, so 84,000 kWh for the gap
- Year total: 450,000 + 84,000 = 534,000 kWh
- Scope 2 (location-based): 534,000 x 0.710 kg CO2 per kWh = 379,140 kg CO2, about 379.1 tonnes
- Estimated share: 84,000 / 534,000 = 15.7% of the year's kWh, disclosed as estimated

If the April bill showed a previous reading, the actual February to March kWh would replace both estimates.

## What Senseible does here

Senseible reads the billing period and kWh from each bill you upload and applies the CEA factor of 0.710 kg CO2 per kWh, so a month with no bill shows as missing rather than as zero. It does not invent figures for missing months; any estimate you add is your own working and is not marked Verified.

- [Footprint from an electricity bill](https://senseible.earth/climate-intelligence/how-to-calculate-carbon-footprint-electricity-bills)
- [Documents needed for carbon verification](https://senseible.earth/climate-intelligence/documents-needed-carbon-verification)
- [Splitting a bill across months](https://senseible.earth/answers/split-electricity-bill-across-months-for-carbon)

Sources: [GHG Protocol Corporate Accounting and Reporting Standard (2004), chapter 7, Managing inventory quality](https://ghgprotocol.org/corporate-standard), [CEA CO2 Baseline Database](https://cea.nic.in/cdm-co2-baseline-database/?lang=en)

Last reviewed 2026-10-15.