TNEB Electricity Bill Calculator (Updated)

Calculating a Tamil Nadu electricity bill manually can become confusing because domestic consumers generally follow a bi-monthly billing cycle, while telescopic energy slabs, 100 free units, fixed demand charges, sanctioned load, and Electricity Duty must be calculated separately.

The TNEB Electricity Bill Calculator is a smart online utility designed for electricity consumers served by TANGEDCO across Tamil Nadu. It helps domestic households, apartment common facilities, commercial establishments, industrial consumers, handloom users, bulk-supply consumers, and supported High Tension connections estimate their electricity expenses before receiving the official bill.

Using the supplied TNERC FY 2026–27 tariff information, the calculator supports the Domestic Home bi-monthly billing cycle, the configured 100 Free Units benefit, telescopic domestic slabs, Commercial LT rates, Industrial LT rates, common-facility charges, fixed demand charges, and 5% Electricity Duty.

The tool can be used by eligible consumers in Chennai, Coimbatore, Madurai, Tiruchirappalli, Salem, Tirunelveli, and other TANGEDCO service areas across Tamil Nadu.

Electricity usage can differ significantly between consumer types. A household in Chennai may use electricity for air conditioning, lighting, refrigeration, and water pumping, while a commercial property in Coimbatore, an industrial unit in Salem, or an apartment common area in Madurai may have higher consumption and sanctioned-load requirements.

The calculator simplifies the complete process by displaying bi-monthly energy charges, the first 100 free units, slab-wise payable units, fixed or demand charges, Electricity Duty, and the estimated net payable amount in a clear itemized report.

What Is the TNEB Electricity Bill Calculator?

The TNEB Electricity Bill Calculator is an online electricity bill estimation tool for Tamil Nadu electricity consumers. Although TNEB is a commonly used public term, electricity distribution services are provided through TANGEDCO under the applicable Tamil Nadu regulatory structure.

The calculator estimates an electricity bill using the total units recorded during the billing period, selected connection category, sanctioned load, and applicable subsidy rules.

Unlike a basic electricity calculator that multiplies all consumed units by one rate, this tool follows the supplied tariff logic for different consumer categories.

For Domestic Home connections, the calculator uses a bi-monthly billing cycle of two months. Therefore, consumers should enter the total units shown for the complete two-month billing period rather than entering an estimated one-month consumption amount.

The supplied Domestic Home tariff slabs are:

• 0–100 units: ₹0 per unit under the configured free-unit benefit
• 101–200 units: ₹4.70 per unit
• 201–400 units: ₹6.30 per unit
• 401–500 units: ₹8.40 per unit
• 501–600 units: ₹9.45 per unit
• 601–800 units: ₹10.50 per unit
• Above 800 units: ₹11.55 per unit

Domestic electricity consumption is calculated using a telescopic structure. This means only the units falling within a particular slab are charged at that slab’s applicable rate.

For example, if a household uses 450 units during a two-month billing cycle, the calculator does not multiply all 450 units by ₹8.40. Instead, it keeps the first 100 units free and distributes the remaining consumption across the applicable payable slabs according to the configured calculation logic.

This bi-monthly slab calculation provides a more useful estimate than a calculator designed for monthly electricity billing.

How the TNEB 100 Free Units Benefit Works

Under the supplied Domestic Home tariff configuration, the first 100 electricity units consumed during the bi-monthly billing period receive a 100% energy-charge benefit.

This means a domestic consumer using 100 units or less may receive a zero estimated energy charge. However, other applicable account-level charges, arrears, adjustments, or statutory components may still affect the official payable amount.

When total bi-monthly consumption exceeds 100 units, the calculator automatically excludes the first 100 units from the energy charge and calculates the remaining units through the configured domestic tariff slabs.

For example, if a domestic household uses 180 units in two months:

• The first 100 units are treated as free.
• The remaining 80 units are calculated using the applicable domestic slab rate.
• Other configured bill components are added separately.

The 100 Free Units option is intended for eligible Domestic Home connections. It should not be applied to Commercial LT, Industrial LT, apartment common facilities, bulk supply, or High Tension categories unless a specific tariff rule provides such a benefit.

Supported TNEB and TANGEDCO Connection Categories

The calculator can support the following categories using the supplied tariff information and configured tariff values:

• Domestic Home Supply
• Apartment and Multi-Tenement Common Facilities
• Commercial LT General Purpose
• Industrial LT and IT Services
• Handloom Connections
• Bulk Supply Connections
• Supported High Tension Categories

Each category may use a different energy rate, fixed charge, billing method, and sanctioned-load calculation. Consumers should select the tariff category printed on their latest electricity bill rather than choosing a category only according to property type.

For apartment and multi-tenement common facilities, the supplied calculator description includes a configured flat energy rate of ₹8.40 per unit and a fixed charge of ₹110 per kW. This category can be used for eligible shared services such as common lighting, lifts, water pumps, and other common-area electricity consumption.

How to Use the TNEB Electricity Bill Calculator

Key Features of the TNEB Electricity Bill Calculator

How the Estimated TNEB Bill Is Prepared

The calculator first identifies the selected consumer category and billing-cycle consumption. Domestic Home units are processed through the configured bi-monthly tariff slabs, with the first 100 units treated as free.

Commercial, industrial, and common-facility connections are calculated using their applicable flat energy rates and sanctioned-load-based fixed charges. The configured 5% Electricity Duty is then calculated according to the taxable components used by the tool.

The final result remains an estimate. An official TANGEDCO bill may include previous arrears, delayed payment surcharge, meter charges, security-deposit adjustments, penalties, tariff revisions, or account-specific corrections.

Why Is Our TNEB Electricity Bill Calculator Different From Other Tools?

A Tamil Nadu electricity bill cannot always be estimated by multiplying the total units by one general tariff rate. Domestic Home connections use a bi-monthly billing cycle, the first 100 units receive the configured free-unit benefit, and the remaining consumption is distributed across telescopic tariff slabs.

Commercial LT, Industrial LT, and apartment common-facility connections follow different energy rates and sanctioned-load-based fixed charges. The monthly fixed charge may also need to be calculated for two months when estimating a complete bi-monthly bill.

The TNEB Electricity Bill Calculator processes these components separately. It identifies the consumer category, applies the correct billing cycle, divides domestic consumption into tariff slabs, deducts the first 100 free units, calculates fixed demand charges, adds the configured 5% Electricity Duty, and displays an itemized estimated bill.

TNEB Domestic Home Bi-Monthly Tariff Slabs

Domestic Home consumption is calculated for the complete two-month billing period. Consumers should enter the total units shown on the bi-monthly bill rather than dividing the reading into two separate months.

How the TNEB 100 Free Units Benefit Is Calculated

Under the supplied Domestic Home calculation structure, the first 100 units consumed during the two-month billing period receive a zero energy charge.

• Consumption up to 100 units: Estimated domestic energy charge is ₹0.
• Consumption above 100 units: Only the units exceeding 100 are distributed across the payable tariff slabs.
• Commercial and industrial categories: The domestic 100-unit benefit is not applied.
• Electricity Duty: Calculated separately according to the taxable components configured in the tool.

A numerical Domestic Home fixed charge was not included in the supplied data. The calculator should therefore use the applicable configured tariff value instead of inserting an assumed amount.

Example: Domestic Consumer Using 180 Units

Suppose a Domestic Home consumer records 180 units during the complete bi-monthly billing period.

• First 100 units: Free
• Remaining 80 units: 80 × ₹4.70 = ₹376
• Estimated energy charge: ₹376
• Other configured charges: Added separately
• Electricity Duty: Calculated according to the configured duty base

The consumer should enter 180 units directly. Dividing the reading into 90 units per month would incorrectly apply the bi-monthly calculation.

Example: Domestic Consumer Using 450 Units

For 450 units, the calculator distributes payable consumption across the applicable slabs.

• First 100 units: Free
• Units 101–200: 100 × ₹4.70 = ₹470
• Units 201–400: 200 × ₹6.30 = ₹1,260
• Units 401–450: 50 × ₹8.40 = ₹420
• Total energy charge: ₹2,150
• Illustrative 5% duty: ₹107.50 when applied only to the energy amount
• Illustrative total: ₹2,257.50 before other applicable charges

The official Electricity Duty base and additional bill components should be checked against the consumer’s actual TANGEDCO bill.

Example: Domestic Consumer Using 850 Units

• First 100 units: Free
• Next 100 units: 100 × ₹4.70 = ₹470
• Next 200 units: 200 × ₹6.30 = ₹1,260
• Next 100 units: 100 × ₹8.40 = ₹840
• Next 100 units: 100 × ₹9.45 = ₹945
• Next 200 units: 200 × ₹10.50 = ₹2,100
• Remaining 50 units: 50 × ₹11.55 = ₹577.50
• Total energy charge: ₹6,192.50 before duty and other charges

Commercial LT General Purpose Tariff

The Commercial LT category may apply to eligible shops, offices, hotels, restaurants, clinics, institutions, showrooms, and other general-purpose non-domestic premises.

• Energy charge: ₹8.80 per unit
• Fixed demand charge: ₹221 per kW per month
• Electricity Duty: 5% under the supplied data

Example: Commercial LT Consumer

Suppose a commercial connection uses 600 units over two months with a sanctioned load of 5 kW.

• Energy charge: 600 × ₹8.80 = ₹5,280
• Two-month fixed charge: 5 × ₹221 × 2 = ₹2,210
• Subtotal before duty: ₹7,490
• Illustrative 5% duty: ₹374.50
• Illustrative estimated total: ₹7,864.50

The billing period must be checked carefully because the supplied fixed demand charge is stated per month.

Industrial LT Tariff

The Industrial LT category may apply to eligible manufacturing units, workshops, processing facilities, IT services, and other qualifying low-tension industrial connections.

• Energy charge: ₹7.65 per unit
• Fixed demand charge: ₹170 per kW per month

Example: Industrial LT Consumer

For 1,000 units over two months with a sanctioned load of 10 kW:

• Energy charge: 1,000 × ₹7.65 = ₹7,650
• Two-month fixed charge: 10 × ₹170 × 2 = ₹3,400
• Subtotal before duty: ₹11,050
• Illustrative 5% duty: ₹552.50
• Illustrative estimated total: ₹11,602.50

Apartment and Multi-Tenement Common Facilities

The supplied calculator description includes a special category for eligible common facilities such as lifts, water pumps, corridor lights, security systems, and shared electrical equipment.

• Energy charge: ₹8.40 per unit
• Fixed demand charge: ₹110 per kW per month
• Domestic 100-unit benefit: Not applied unless specifically allowed by the tariff

For a two-month bill, the monthly fixed charge should be multiplied by two when the calculator is estimating the complete bi-monthly period.

How the Estimated TNEB Bill Is Calculated

1. Select the correct tariff category.
2. Enter total consumption for the applicable billing period.
3. Use the bi-monthly total for Domestic Home connections.
4. Enter sanctioned load in kW or kVA where required.
5. Apply the first 100 free units only to eligible domestic consumption.
6. Calculate payable domestic units through the configured slabs.
7. Add monthly fixed charges for the number of months in the bill.
8. Calculate the configured 5% Electricity Duty.
9. Display every component and the estimated payable amount.

The official TANGEDCO bill may also include arrears, delayed payment surcharge, meter charges, security-deposit adjustments, penalties, tariff revisions, or account-specific corrections.

Electricity-Saving Tips for TNEB Consumers

• Track total usage throughout the two-month billing period.
• Monitor consumption when approaching 100, 200, 400, 500, 600, and 800 units.
• Use LED lighting and energy-efficient fans.
• Set air conditioners near 24–26°C and clean filters regularly.
• Switch off unused appliances and standby devices.
• Maintain refrigerators, water pumps, lifts, and industrial equipment.
• Compare the current meter reading with previous TANGEDCO bills.
• Enter the correct sanctioned load for non-domestic calculations.

Frequently Asked Questions