How to Use the WJEC Biology Grade Calculator
A complete guide to understanding your UMS results, planning AS resits, and analysing mock exams with our free WJEC A-Level Biology tool.
Which Tool Should I Use?
The WJEC Biology Grade Calculator has two main tools, each designed for different situations:
| Tool | When to Use | What It Does |
|---|---|---|
| 📊 UMS Analyser | Results day, during Year 13, or when planning AS resits | Enter your unit marks (UMS or raw), see your predicted grade, what you need in remaining units, and calculate the impact of resitting AS |
| 🔍 Mock Exam Analyser | After mock exams, during revision | Enter mock scores to see UMS equivalents, unit grades, and overall AS/A-Level grades |
Understanding UMS & Raw Marks
WJEC uses the Uniform Mark Scale (UMS) to ensure fair comparison between exam sessions. Here’s what you need to know:
- Raw Marks
- The actual marks you score on each exam paper (e.g., 58 out of 80 for Unit 1). Raw mark boundaries change each year depending on paper difficulty.
- UMS (Uniform Mark Scale)
- A standardised score that allows fair comparison across different exam sessions. Your raw marks are converted to UMS using boundaries set after marking. UMS grade boundaries are fixed every year.
- Grade Boundaries (UMS)
- The minimum total UMS needed for each grade: A/A* = 400, B = 350, C = 300, D = 250, E = 200 (out of 500 total). For A* you also need 270+ from A2 units.
The Five Units
| Unit | Name | Level | Max Raw | Max UMS | Weight |
|---|---|---|---|---|---|
| 1 | Basic Biochemistry & Cell Organisation | AS | 80 | 100 | 20% |
| 2 | Biodiversity & Physiology of Body Systems | AS | 80 | 100 | 20% |
| 3 | Energy, Homeostasis & Environment | A2 | 90 | 125 | 25% |
| 4 | Variation, Inheritance & Options | A2 | 90 | 125 | 25% |
| 5 | Practical Examination | A2 | 50 | 50 | 10% |
| Total | — | 500 | 100% | ||
Using the UMS Analyser
Use this tool when you have actual results (or to model different scenarios). It calculates your predicted grade and shows what you need in remaining units.
Select Grade Boundaries Year
Choose the year for raw-to-UMS conversion (2022–2024). Only relevant if entering raw marks.
Choose Input Type
Select UMS Marks (from your results slip) or Raw Marks (actual exam scores). If using raw marks, the tool converts them to UMS automatically.
Enter Your Unit Marks
Input marks for completed units. Tick “Not taken” for units you haven’t sat yet — the tool will calculate what you need in those units.
Select Your Target Grade
Choose the grade you’re aiming for (A* to E). The tool shows how many UMS you need and how difficult it will be.
Click “Calculate My Grade”
See your current UMS total, predicted grade, what you need per remaining unit, and personalised strategic advice.
Understanding Your Results
- Current UMS Total: Your combined UMS across completed units
- Max Possible UMS: The most you could achieve if you scored maximum on all remaining units
- UMS Needed for Target: How many more UMS you need to reach your target grade
- Current Trajectory: Your predicted grade assuming 70% on remaining units
- Difficulty Badges: Achievable (≤60%), Challenging (61–75%), Difficult (76%+)
Using the Resit Impact Calculator
The Resit Calculator appears after you’ve calculated your grade. It helps you see how improving your AS marks would change your position.
First Calculate Your Grade
Enter your current marks and click “Calculate My Grade” to see your results.
Enter Expected Resit UMS
In the Resit Impact Calculator section, enter your expected UMS for Unit 1 and/or Unit 2. Be realistic about what you could achieve.
Click “Calculate Resit Impact”
The tool shows your new UMS total, how many marks you’d gain, updated requirements for A2 units, and your new predicted grade.
When Is Resitting Worth It?
- Your AS average is below 70 UMS per unit and you’re aiming for an A or above
- You had circumstances that affected your AS performance
- Improving AS marks would significantly reduce pressure on your A2 exams
- You’re confident you can manage 5 biology exams in one session
Using the Mock Exam Analyser
Use this tool after mock exams to see your UMS equivalents and predicted grades. You can enter results for any combination of units.
Select Grade Boundaries Year
Choose which year’s raw-to-UMS boundaries to compare against. 2024 is most recent.
Choose Input Type
Select Percentage, Raw Marks, or UMS depending on how your mock results were given.
Enter Your Mock Scores
Input scores for each unit you’ve done a mock for. Leave blank for units you haven’t tested.
Click “Analyse My Mock Results”
The tool shows your UMS equivalents, unit grades (a–e), and overall AS and A-Level grades.
Tips & Common Questions
Raw marks are your actual exam score (e.g., 58/80). UMS (Uniform Mark Scale) is a standardised score that allows fair comparison across different exam sessions. Raw boundaries change each year based on paper difficulty, but UMS grade boundaries stay the same. Your results slip shows UMS marks.
For an A* you need a total of 400 UMS marks AND at least 270 UMS from your A2 units (Units 3, 4, and 5). This means you need to score 90% across your A2 units. Both conditions must be met.
Yes, WJEC allows you to resit individual AS units (Units 1 and 2). Your best score for each unit counts. However, resitting means sitting those exams alongside your A2 exams, so you could have up to 5 biology exams in one session. Discuss this with your teacher.
For actual results using UMS marks, the calculator is completely accurate as UMS grade boundaries are fixed. For mocks using raw marks or percentages, accuracy depends on how representative your mock papers were and which year’s boundaries you compare against.
WJEC is for Wales and uses a modular structure with 5 units, UMS marks, and AS results counting towards the final A-Level. Eduqas is for England and is a linear qualification with 3 components using raw marks only, where all exams are sat at the end of Year 13.
📚 Data Sources & Official Resources
All raw-to-UMS conversions use official WJEC grade boundary data from 2022–2024.
- WJEC Mark to UMS Converter — Official interactive boundary lookup tool
- WJEC A Level Biology — Official specification, past papers and resources
- WJEC Grade Boundaries — Full archive of all boundaries
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Book a Session →Disclaimer: This guide is for educational purposes only. Always verify with official WJEC documents. Biology Education and its author accept no responsibility for individual exam outcomes.
Copyright Acknowledgement: WJEC, Eduqas and CBAC are registered trademarks of WJEC CBAC Ltd. Grade boundary data referenced on this page is © WJEC CBAC Ltd and is reproduced here solely for non-commercial educational purposes. For official grade boundaries, visit wjec.co.uk.