This new Switchwise calculator enables you to compare your old and new tariff monthly payments. Old tariffs may expire within the year so you are probably looking to switch. Using this calculator you can see the real difference in your average monthly direct debit payments. Full page version.  
1. First enter how much energy you use in a year.
Change figures to 0 where you do not use either gas or electric.   kWh's pa      
Gas - Consumption in kWh's PA 1  Gas kWh's pa    
Elec - Total kWh's used PA 2  Elec kWh's pa    
2. If you have electricity economy 7, enter the percentage night use.
If you have a standard meter, leave this at 0%   E7 Night %      
Elec - % night use (Only for E7) 3  E7 Night %    
3. Enter your old and new gas tariffs   Old tariffs New tariffs
Your tariff is made up of standing charge, and rate per kWh used.  
GAS   Old Gas New Gas    
Gas - Daily standing charge 4 ppd  
Gas - Unit rate per kWh 5 ppkwh  
ELECTRICITY   Old Elec New Elec    
Elec - Daily standing charge 6 ppd  
Elec - Day rate 7 ppkwh  
Elec - E7 Night rate (Only for E7)   ppkwh  
4. Finally, enter your discounts for each tariff  
Change figures to 0 where you do not get discounts.   Old Discounts New Discounts    
Dual fuel Discount (INC vat) 8 £'s/pa  
Single fuel discount (INC vat)   £'s/pa  
Online Billing Discount   £'s/pa  
Direct Debit Discount (INC vat)   £'s/pa  
RESULTS   Old Costs New Costs
Total costs including VAT - Old tariff / New tariff Costs pa
Savings per year Savings pa
Cost Savings % Savings %
Cost per month - Old tariff / New tariff Cost pm
Savings per month Savings pm      
Disclaimer: Use this calculator as a guide but check your own comparisons manually before making a decision.
For full energy price comparisons and links to switching service, use:
If you don't have exact consumptions try these typical amounts: GAS STD ELEC E7 ELEC
Small house or flat 11000 2100 2500
Medium house 16500 3300 4300
Large house 23000 5100 7200    
Guidance notes:
1. Enter your total gas consumption used in kWh's for a 1 year period.
2. Enter you total electric kWh's for a year.
3. If you have Economy 7, enter the % night usage.
5. Enter cost in pence per kWh for old and new tariffs
6. Enter daily standing charge for old and new tariffs.
7. Enter cost in pence per kWh for old and new tariffs
Check these calculations carefully. This calculator is only a guide.
Please use Switchwise to make your actual transfer. Same results as all others. Thanks! :)