UCAT Unit Conversions Trainer
Practise metric units, time, rates and per-100 conversions for UCAT QR.
Written and reviewed by Dr Akash Gandhi, NHS GP (GMC 7601216) and founder of TheUKCATPeople, teaching the UCAT since 2012. Last reviewed .
Frequently asked questions
What does the UCAT unit conversions trainer practise?
It drills the unit changes hidden inside UCAT Quantitative Reasoning questions: metric length, mass and volume, time, speed and time, per 100 g rates, doses and rates, money and exchange rates, area and volume, and full portions, such as how many whole servings a pack makes. Each drill mixes these categories and you type each answer as a number. It is free and sits in the Quantitative Reasoning hub alongside the calculator and mental maths trainers.
How does the unit conversions trainer work?
Read the question, note the unit the answer must be in, and type a number. A timer shows how long you spend on each question, because QR rewards speed. After you submit, the trainer shows the correct answer and a worked explanation in four parts: the method, an exam shortcut, a sense check and the common trap behind wrong answers. You can step back and forward between questions, and your results are saved as you go.
Which unit conversions do I need to know for UCAT Quantitative Reasoning?
Know the metric steps by heart: 1 km = 1,000 m, 1 m = 100 cm, 1 cm = 10 mm, 1 kg = 1,000 g, 1 g = 1,000 mg and 1 litre = 1,000 ml. Add time (60 minutes in an hour, 60 seconds in a minute), 100 pence in a pound, and the volume link 1 ml = 1 cm³. Less familiar rates, such as exchange rates, are given in the question, so the skill there is applying the rate in the right direction.
How do I convert cm² to m² and litres to cm³?
Square or cube the length factor. There are 100 cm in a metre, so 1 m² = 100 × 100 = 10,000 cm², and 25,000 cm² is 2.5 m². For volume, 1 m³ = 1,000,000 cm³, while 1 litre = 1,000 cm³ and 1 ml = 1 cm³, so 3.2 litres is 3,200 cm³. The usual trap is dividing cm² by 100 instead of 10,000, which the trainer's explanations flag as using a length conversion for an area.
How do I convert minutes to hours in UCAT speed questions?
Divide minutes by 60 before using speed = distance ÷ time. 35 minutes is 35 ÷ 60, about 0.58 hours, so at 96 km/h you travel 96 × 35 ÷ 60 = 56 km. Watch the classic trap: 1.5 hours is 1 hour 30 minutes, not 1 hour 50 minutes, and 2 hours 15 minutes is 2.25 hours. Converting first and then calculating is quicker on the on-screen calculator than working with mixed units.
How do I avoid unit mistakes in UCAT Quantitative Reasoning?
Check the unit the answer options use before you calculate, convert every value into that unit first, then do the sum. Finish with a sense check: converting to a smaller unit should give a bigger number, and a dose or price should be realistic. Watch rounding rules too: a question about how many full portions you can make needs rounding down, not rounding to the nearest whole number.