Free tools

Free L1R5 calculator

No signup. No ads. No data leaves your browser. Built by ExamExplained for SG-A-LEVEL, SG-O-LEVEL and SG-N-LEVEL students.

Enter your O-Level subject grades to work out your L1R5 aggregate (English plus your best five relevant subjects). Lower is better.

Subject calculators

Projectile motion, circular motion, gravitation, waves, electromagnetism, and quantum/atomic — every key formula as a quick calculator.

pH and pOH, weak-acid and buffer pH, equilibrium constant, Ksp, dilution, titration, mole conversion, Beer-Lambert and calorimetry.

Punnett squares, sex-linked inheritance, Hardy-Weinberg equilibrium, and population-growth calculators.

Work out the exact mark you need on your final exam to hit your target overall grade.

These are free study estimators, not official tools. For official admissions information and entry requirements, see SEAB.