English learning calculator

A target below the current band fails with invalid_input and is not billed. Use the page in your browser at no charge, or call the API at $0.002 per successful request when a learning-app onboarding flow or a tutoring plan needs the identical figure.

How study hours and days are computed from your English levels

The engine counts how many rungs sit strictly above the current band and up to and including the target: A1 to B1 is two rungs, A1 to A2 and then A2 to B1; A2 to C1 is three rungs; A0 to C2 is six rungs. The response echoes the cleaned current_level, target_level, daily_minutes, and hours_per_level, then returns levels_to_climb, the path of bands from the start through the target, total_hours, daily_hours, total_days as the exact quotient, total_days_ceil as the smallest whole calendar day that covers that quotient, weeks as total_days divided by seven, already_at_target, a level_steps table with one row per rung, plus a formula string, a one-line message, and numbered steps. This endpoint does not fetch a placement score, does not award a certificate, and does not apply rest days, holidays, or time zones. It answers one question: if you hold this English band, want that band, budget this many minutes a day, and accept this many hours per rung, how many days is the climb.

Input contract, inverted levels, response fields, and validation errors

Zero and negative minutes or hours fail because a plan with no daily time or a zero-hour rung cannot move anyone up the ladder, and a zero daily rate would be a division by zero. Magnitudes above the documented ceilings — one thousand four hundred forty minutes in a day, ten thousand hours per level — fail so a typo cannot blow the isolate. A familiar check is A1 to B1 at thirty minutes a day and two hundred hours per level, which yields two rungs, four hundred hours, one half hour per day, and eight hundred days. POST a JSON body with four required fields. current_level is the CEFR band you hold now: A0, A1, A2, B1, B2, C1, or C2, in any letter case. Aliases current, from, from_level, level_from, and start_level map to the same field. target_level is the band you want to reach, with the same closed list; aliases target, to, to_level, level_to, and goal_level are accepted. daily_minutes is the strictly positive number of study minutes you can keep every calendar day; aliases minutes, minutes_per_day, daily, and pace are accepted. hours_per_level is the strictly positive planning rate of guided hours you assign to each CEFR rung; aliases hours_each, per_level, hours_band, and level_hours are accepted. Every numeric field may arrive as a JSON number or as a numeric string that coerces to a finite number. Booleans, objects, empty strings, NaN, and Infinity fail with invalid_input. If target_level sits strictly below current_level on the CEFR ladder the request fails and names target_level, because going backwards is not a study plan. When the two bands are equal the climb is already done: levels_to_climb, total_hours, and total_days are zero and already_at_target is true. Missing fields and inverted levels are invalid_input and are not billed. Successful API calls use the published $0.002 base price; the free browser path runs the same solve function without consuming prepaid balance.

Self-study plans, schools, tutors, and product integrations

Independent learners open an English learning calculator when the question is not what level a diary of hours already supports, but how long the remaining climb will take at the minutes they actually have. Language schools use the same four fields to turn a brochure promise into a shared number: three rungs at one hundred fifty classroom hours and sixty minutes a day is four hundred fifty hours and four hundred fifty days, which is honest in a parent meeting. Failed validation does not consume balance. A working adult at A2 who wants B2 for a visa or a job, with forty-five minutes after dinner and a conservative two hundred hours per band, can read total_days and weeks before they sign a year-long course. Tutors open intake sessions with current_level set to the last certified band and hours_per_level set to the pace they actually teach, so only the remaining climb is priced. Product teams wiring onboarding for a vocabulary or tutoring app call the same parse endpoint from an edge worker because the algorithm is a ladder index, a product, and a quotient — no model tokens and no outbound network. Keep hours_per_level as a planning estimate your users understand, pin total_days in your tests, and combine the result with a skills-based placement when you need certification readiness. This tool answers the calendar question; it does not replace an examiner, and it does not invent rest days or exam cut scores you did not send.