American universities do not admit international students without proof of English proficiency. The format of that proof may vary, but the logic is the same: the university needs to be sure that the student can understand lectures, write papers, and take part in academic discussions. Several standardised exams exist for this purpose, and choosing between them isn't just a formality.
How the Main Exams Differ
TOEFL iBT remains the most common option for US institutions. Since January 2026, the exam uses a new scale — from 1 to 6 in 0.5 increments — which replaced the previous 120-point system. The test is now shorter: about 90 minutes instead of two hours. Results are available within 72 hours. The old format is still in use during the transition period, so when submitting documents it is important to check which scale a particular university uses.
IELTS Academic uses a scale from 0 to 9. The exam takes about 2 hours 45 minutes, and results come in 3–5 days. From 2026, IELTS is moving entirely to a computer-based format, and the One Skill Retake option allows you to retake one section — writing, reading, listening, or speaking — within 60 days of the main test, without having to sit the whole exam again. In the US this option is not yet available, but for applicants taking the exam in other countries it is accessible.
The Duolingo English Test stands apart. The exam lasts about an hour and costs $70, compared with $200–250 for TOEFL and IELTS. Results arrive within 48 hours. The main limitation is that not all universities accept it. If an institution has included Duolingo on its list of approved exams, it's the fastest and cheapest way to prove your English level. If not, you will have to take TOEFL or IELTS.
What Scores Are Considered Sufficient
Minimum requirements vary depending on the type of institution. For undergraduate programmes at mid-tier public universities, TOEFL iBT 79–80 or IELTS 6.0–6.5 is usually sufficient. Duolingo is accepted at such institutions with a score of 95 to 105. For master's programmes, requirements are higher: TOEFL 80–90, IELTS 6.5–7.0, Duolingo 110–120.
In competitive programmes, the bar is even higher. Engineering and business fields at top-50 universities often require TOEFL 100+ or IELTS 7.5+. For admission to Harvard, Stanford, or MIT, a minimum threshold may not even be stated — they look at the overall picture — but a realistic competitive score rarely falls below TOEFL 110 or IELTS 8.0.
Section requirements also matter. Many universities set not only an overall score but also a minimum for each part of the exam. For example, to be admitted to engineering programmes, you may need not just an overall IELTS 6.5 but also at least 6.0 in writing and reading.
What to Do If Your Score Is Below the Required Level
A score below the cut-off doesn't mean rejection. Most American universities offer conditional admission. The student receives a letter saying they are academically suitable but must first improve their language skills. The conditions vary: some institutions require you to retake the exam and reach the required score before classes start; others enrol you in the university's language centre and allow you to begin academic courses only after completing the programme.
There are several formats for such preparation. The Intensive English Program (IEP) is an academic English course that can last from one semester to a year. Many universities waive the TOEFL or IELTS requirement for those who successfully complete an IEP at the same institution. Bridging courses are short programmes in specific subjects, for students whose language is fine but who lack academic background in maths or science. Pathway programmes are year-long and combine language training with credit-bearing courses: the student is conditionally admitted to the bachelor's programme in advance and starts studying without losing time.
How to Prepare for the Exam
The choice of exam depends on two factors: which tests a particular university accepts and which format is more convenient for the student. TOEFL focuses more on academic English and is widely accepted in the US. IELTS is universal and accepted in most countries. Duolingo is faster and cheaper but not recognised everywhere.
Preparation takes from one to three months, depending on your starting level. For TOEFL and IELTS, it is useful to practise the format: timing, question types, strategies for each section. Duolingo requires less format preparation but tests real skills — the answers are hard to guess. If your result is lower than expected, IELTS allows you to retake one section, while TOEFL allows you to register for a retake after 12 days.
The main thing is not to leave the exam to the last moment. Results are valid for two years, but university application deadlines often fall six months before the start of studies. If your score falls short, the time for a retake or for arranging conditional admission may be limited.