Compare business electricity contracts on identical usage
This calculator applies two eligible Korean general-service tariffs to the same twelve months of electricity use.
It compares monthly bills, the annual difference, first-year savings after switching costs and the month when those costs are recovered.
A lower basic charge or one inexpensive billing month does not establish the cheapest annual contract: heating, cooling and operating hours can change the result.
Korea-based scope: 2026
This is for small-business operators, owners of mixed home-and-shop buildings and families reviewing a parent’s shop expenses.
Business registration alone does not establish tariff eligibility; confirm the actual use, supply voltage and contract conditions with Korea Electric Power Corporation (KEPCO).
Residential progressive tiers, electrical capacity upgrades and industrial tariffs require other calculations.
Prepare evidence before entering figures
Gather twelve electricity statements, contract information, eligible tariff schedules, meter requirements and a switching quote.
Mark each group of inputs as confirmed, assumed or unknown so that a planning scenario is distinguishable from a calculation based on actual records.
Contract and tariff records
Enter the general-service class, voltage, option, basic rate and seasonal energy rates.
Record both the effective date and the date through which the rates have been verified, plus a schedule title or consultation reference.
Unconfirmed eligibility does not produce a reliable annual comparison.
Statements and switching quote
Record billed kW, usage by time band, climate and fuel rates, and any supply-subtotal adjustments.
Use the VAT-inclusive total cost of the meter change and associated work.
A verified zero cost is different from a quote that has not yet been obtained.
Confirmation is user-reported evidence, rather than automatic institutional verification.
Projections and copied monthly values should be marked assumed.
Unknown months remain pending, and missing amounts are never silently replaced with zero in the annual total.
Contract capacity is different from billed power
Contract capacity is the agreed supply capacity; billed power is the kW quantity used to calculate a particular basic charge.
Recorded maximum demand and minimum billing rules can make the two figures different.
Enter the billed kW from each statement instead of assuming that contract capacity directly determines every monthly basic charge.
- General (A) type I supports seasonal flat-rate options I and II.
- General (A) type II uses time-of-use options I and II, or seasonal flat-rate options III and IV.
- General (B) supports time-of-use options I, II and III.
- This tool does not support low-voltage General (A) type II or General (B). Comparisons between different supply voltages remain pending.
KEPCO must confirm the eligible contract and metering arrangement.
A low modeled price does not authorize a change.
Enter any verified power-factor adjustment in the supply-adjustment field and separately check excess-use charges if billed power exceeds contract capacity.
Seasonal and time-band classification
Summer
June–August use the entered summer rates.
Spring/autumn
March–May and September–October use shoulder-season rates.
Winter
November–February use the entered winter rates.
KEPCO implemented revised time bands for General (A) type II and certain other services on 2026-06-01.
For weekdays in March–October, 11:00–12:00 and 13:00–15:00 moved from peak to mid-peak, while 18:00–21:00 moved from mid-peak to peak.
Identical opening hours can therefore produce different classified kWh before and after the revision.
The calculator accepts off-peak, mid-peak and peak kWh already classified under the applicable schedule; it does not infer them from clock times.
Reconcile weekends, holidays, revised schedules and meter-reading periods before entering the figures.
A flat-rate candidate receives the same total kWh as the time-of-use candidate.
From basic charges to VAT and the fund levy
Planning formulas
- Basic charge = billed kW × basic rate. Energy charge = the sum of each time-band usage × its seasonal rate.
- Climate charge = total kWh × entered climate rate. Fuel adjustment = total kWh × entered signed fuel rate.
- Supply subtotal = basic + energy + climate + fuel + the contract-specific supply adjustment.
- VAT is 10% of the supply subtotal. The electricity-industry fund levy is 2.7% of that subtotal.
This planning model floors basic, energy and climate amounts to whole KRW, and truncates signed fuel amounts toward zero.
VAT is rounded to the nearest KRW, the fund levy is floored to a multiple of KRW 10, and the final comparison bill is floored to a multiple of KRW 10.
Reconcile these conventions with the actual statement, particularly where a mid-period contract change requires separate calculations.
Climate and fuel rates start blank because they require period-specific verification.
Supply adjustments must belong to the same VAT and fund-levy base.
Late fees, exemptions, minimum-levy exceptions and partial-period billing are outside this model. A negative supply subtotal makes that month pending.
Temporary lower-tariff billing: June–November 2026
General (A) type II only
KEPCO compares options I↔III or II↔IV each month and automatically bills the lower energy charge for June–November 2026, with the same basic charge.
Savings already delivered through that mechanism should not be counted again as a new benefit from switching contracts.
The calculator applies the lower energy charge to both sides only for an eligible pair with the same voltage, basic rate and monthly supply adjustments.
Thus, a lower raw price for option III can still produce zero actual difference from option I during the relief window.
If the required counterpart or matching terms are absent, that month’s applied comparison is withheld.
The mechanism is not applied in May or December.
Industrial (B) and electric-vehicle weekend discounts are outside this general-service tool.
Confirm the choice process and actual billing arrangements after the temporary period ends.
Step-by-step use
- Enter contract capacity and meter confirmation, then choose the evidence status of usage and additional charges.
- Complete current contract A and candidate B: eligibility, voltage, option, basic rate, seasonal rates and validity dates.
- Copy billed power, classified usage, climate and fuel rates, and both adjustments from each of the twelve statements.
- Enter a VAT-inclusive switching quote and its reference. The annual tariff difference can still be calculated while the quote is unknown.
- Press Compare, review pending reasons and assumed months, then save the TXT worksheet for a KEPCO consultation.
Numeric inputs support decimals and comma-separated values; fuel rates and supply adjustments also support negative values.
Copying January to the remaining months changes usage and additional-charge evidence to assumed.
Editing inputs hides the previous result until the comparison is recalculated.
A synthetic worked example
These figures are fictional arithmetic inputs, not an official KEPCO tariff schedule.
Assume billed power of 10 kW, a basic rate of KRW 6,000/kW and monthly usage of 400/300/300 kWh in the off-, mid- and peak bands.
A uses rates of 100/150/200 KRW/kWh; B uses a flat rate of 140 KRW/kWh in every season.
Climate and fuel inputs are 9 and 5 KRW/kWh, both supply adjustments are zero, and the switching quote is KRW 20,000.
Synthetic 2026 option I and III energy charges and annual bill comparison| Item | A · option I | B · option III |
|---|
| Raw monthly energy charge | KRW 145,000 | KRW 140,000 |
| Monthly bill before temporary relief | KRW 246,810 | KRW 241,170 |
| Monthly applied bill: June–November | KRW 241,170 | KRW 241,170 |
| Annual applied bill | KRW 2,927,880 | KRW 2,894,040 |
The actual modeled annual difference is KRW 33,840; first-year net savings after switching are KRW 13,840.
The raw annual difference of KRW 67,680 would overstate the switching benefit by ignoring automatic lower-tariff billing.
With the cost paid in January, month 4 is the first recovery point that remains recovered through December.
Use this example to understand the worksheet, then replace every fictional input with site-specific evidence.
Interpret savings, pending results and recovery
Annual savings equal applied A bills minus applied B bills.
Positive values favor B; negative values favor A. A result that favors keeping the current contract is retained.
An unknown switching quote withholds first-year net savings and recovery, while leaving a calculable annual tariff difference visible.
Preserve confirmed and assumed evidence
A month is assumed if the rate validity does not cover the entire billing month.
Applying a June schedule to January does not reproduce a confirmed historical bill.
When split readings for a revision month are unavailable, use the output as a consultation scenario.
Recovery assumes an upfront cost in January and examines only these twelve months of 2026.
A temporary crossing followed by a seasonal shortfall is not reported as sustained recovery.
If the cost has not been recovered by December, the result says it was not recovered within the modeled twelve months; temporary relief is never extrapolated indefinitely.
Practical scenarios and limits
Different operating hours
A daytime shop and a restaurant with evening heating or cooling can have identical total kWh but different time-of-use costs.
Start by comparing eligible tariff choices using actual classified usage.
A meter-change quote
A cheaper ongoing tariff can still produce a first-year loss when installation costs are substantial.
Save the quote scope alongside the comparison, and confirm when savings would start after the real change date.
This tool does not determine eligibility, change a contract, design a capacity upgrade or estimate real-time usage.
It does not calculate industrial, educational or residential tariffs.
If a contract change would alter billed power or time-band classification, ask KEPCO whether the identical-input comparison remains appropriate.
Check change restrictions, cancellation costs, construction, partial periods and any special taxes or levies separately.
Frequently asked questions
Can any business freely choose a general-service tariff?
No.
Confirm the actual use, supply voltage, contract conditions and meter requirements with KEPCO.
Unknown or ineligible candidates do not establish annual savings.
Is total monthly kWh enough for a time-of-use comparison?
A time-of-use tariff needs off-, mid- and peak usage.
Arbitrary allocations are assumptions; obtain readings classified under the applicable schedule before making a contract decision.
Does automatic lower-tariff billing continue in December 2026?
This model applies the verified mechanism only to June–November 2026.
Confirm the process and any later announcements for December; the temporary period is not extended indefinitely.
Why are relief months pending for other tariff pairs?
Comparing options I and II alone omits their flat-rate counterparts III and IV, so the actual lower bills cannot be determined.
Enter the supported equal-basic-charge pair or obtain actual billing figures from KEPCO.
Why not multiply contract capacity directly by the basic rate?
Billed power can differ because of demand records and contractual rules.
Enter each monthly billed-kW figure, and verify power-factor and excess-use charges separately.
How is zero different from a blank?
A verified zero is usable.
A blank remains unknown and is not omitted or replaced with zero.
An unknown switching quote withholds only first-year savings and recovery when annual bills are otherwise available.
Are the example prices actual KEPCO rates?
No.
Basic 6,000, time-band 100/150/200, flat 140, climate 9 and fuel 5 are synthetic arithmetic inputs.
Enter actual rates for your eligible contract and billing period from KEPCO ON.
Can I save the result for a consultation?
TXT preserves inputs, references, validity dates, evidence status, monthly breakdowns, temporary relief and pending reasons.
Printing is also available; neither replaces a change application or KEPCO approval.
Official sources and the next step
Sources verified on 2026-10-15.
The official legislation API was used to check Electricity Business Act MST284383 Articles 16/51 and Enforcement Decree MST288907 Articles 7/36, effective 2026-09-18; VAT Act MST276117 Article 30 is effective 2026-01-02.
Recheck actual rates, eligibility, meter conditions, VAT, the fund levy, rounding and the end of temporary arrangements whenever rates or the rule year change.
Enter verified contract details, meter records, rate schedules and the switching quote, then save the comparison.
Review eligibility, the choice process from December and the actual change date with KEPCO ON or the Korean electricity service line 123.