Charging Guide
Tesla Charging Budget and SOC Calculation Guide
This page explains how Tesla Charge Limit Calculator turns a charging budget into target SOC, battery input energy, added range, and EV-versus-ICE cost comparison. The calculator does not control the vehicle; it is a planning reference based on the amount, energy price, and vehicle battery assumptions you enter.
Content updated: May 7, 2026
Method
Cost-based SOC workflow
- Paid kWh = charging budget / price per kWh
- Battery input kWh = paid kWh x (1 - charging loss rate)
- SOC gain = battery input kWh / current usable battery capacity x 100
- Target SOC = current SOC + SOC gain. If the result exceeds 100%, the calculator also shows the maximum realistic charge amount.
- Added range = battery input kWh x 1000 / vehicle Wh/km consumption
The same budget can produce different results because usable capacity, charging loss, degradation, and efficiency differ by vehicle and charging method.
Example
Example calculation
If current SOC is 20%, current usable capacity is 75 kWh, energy price is 339 KRW/kWh, charging budget is 20,000 KRW, and loss rate is 10%, the paid energy is about 59.0 kWh and the battery input is about 53.1 kWh. The SOC gain is about 70.8 percentage points, so the target SOC is about 91%.
This is a planning estimate. Real final SOC and displayed kWh can vary with charger power limits, battery temperature, preconditioning, tapering near the end of charge, and vehicle software.
Charging Loss
Why charging loss differs by method
| Charging method |
Default loss |
How to read it |
| Supercharger |
About 8% |
Often efficient when vehicle and charger conditions are good, but high-power segments and temperature still matter. |
| General DC fast charging |
About 10% |
Set slightly more conservative than Supercharging to account for charger condition, cable condition, and battery temperature. |
| AC charging |
About 12% |
Most conservative because onboard AC-DC conversion, standby power, and long charging time add overhead. |
Battery
How to interpret LFP and NMC-style batteries
LFP packs are often guided toward periodic 100% calibration, while many NMC/NCA owners target roughly 80-90% for daily use. The vehicle screen and manufacturer guidance come first; this site provides planning context, not maintenance instructions.
The calculator uses battery chemistry only for habit notes. Actual SOC calculation uses the vehicle usable capacity and any degradation correction entered by the user.
Interpretation
How to read the result
- If the budget pushes target SOC above 100%, also check the maximum chargeable amount shown by the calculator.
- Electricity prices vary by region, operator, time, and membership plan, so replace the default rate with your actual price.
- Added range is a reference value converted from the calculator's vehicle Wh/km assumptions, not an official certified range.
- If degradation matters, use the main calculator's Rated Range input or precision mode to adjust current usable capacity.