Bill amount → units consumed
Have a taka total but not the unit count? Enter the bill and sanctioned load, and this tool works backwards through the LT-A slabs to estimate consumption.
Estimated result
Enter your bill total and press Calculate units to see the estimated consumption and slab breakdown.
Why reverse-calculating units isn't simple division
Because Bangladesh's residential tariff is progressive rather than flat, you cannot recover consumption from a bill total by dividing by a single rate — the answer depends on which slabs the consumption passed through on the way up. This tool instead performs a binary search: it repeatedly guesses a consumption figure, runs it through the exact same slab function the main calculator uses, and narrows the guess until the resulting energy charge matches your bill's implied energy charge (after removing VAT and the demand charge). The process converges to a very close estimate within a few dozen iterations, all happening instantly in your browser.
The two adjustments before solving matter: VAT is a flat percentage of the whole subtotal, so it has to be stripped out first, and the demand charge is a fixed amount tied to sanctioned load rather than usage, so it also has to be removed before the remaining figure represents pure energy consumption. If your actual bill includes a meter rent line or a fuel-adjustment surcharge, subtract those manually first for a cleaner estimate, since the calculator has no way to detect them from the total alone.