Awaiting input
Fill in the fields and press Calculate. Your result appears here and stays in view as you scroll.
The guide
Understanding the Grade
Weight each assessment to find your current grade, the letter it maps to, and what the final exam needs to score.
What each input means
The calculator asks for 3 pieces of information. Every field is validated before the maths runs, so an impossible value is refused rather than quietly producing a wrong answer.
| Input | What it asks for | Example |
|---|---|---|
| Scores received (%) | One per assessment, comma or space separated. | 85, 92, 78 |
| Weight of each (%) | Must match the scores in order. These should add up to 100. | 30, 40, 30 |
| Target overall grade | Optional — works out what the remaining assessment needs to score. | Blank |
A worked example using the default inputs
With scores received (%) of 85, 92, 78, weight of each (%) of 30, 40, 30, target overall grade of %, the calculator returns 85.7% B on a standard scale.
| Result line | Value |
|---|---|
| Current grade | 85.7% B on a standard scale |
| Letter grade | B |
| Total marks earned | 85.7 of 100 weighted points |
| Weight graded so far | 100% |
| Weight still to come | 0% |
| Highest score so far | 92.0% |
The same arithmetic runs whatever you type into the form above, so you can reproduce any figure by matching the inputs listed here.
How this is calculated
Grade = Σ(score × weight) ÷ Σ(weight). The score still needed = (target − marks earned) ÷ weight remaining × 100.
Working values are kept at full precision and rounded only for display. Impossible dates, zero denominators, negative amounts where they make no sense, and out-of-range values are rejected before any result is shown.
What these everyday tools assume
Everyday calculators turn measurements you can measure with a tape and a receipt into quantities you can buy. They are deliberately rounded and deliberately conservative, and every one of them depends on a rate you supply rather than a rate you can look up.
| Tool family | The arithmetic | Where it is used |
|---|---|---|
| Percentage off | Final = price × (1 − discount ÷ 100) | Discount, tip and split |
| Coverage | Litres = area × coats ÷ coverage per litre | Paint |
| Volume with waste | Volume = length × width × depth, plus 5 to 10% | Concrete |
| Weighted average | GPA = Σ(grade points × credits) ÷ Σ credits | GPA, grade |
| Network split | Usable hosts = 2^(32 − prefix) − 2 | Subnet |
| Password strength | Bits = length × log₂(size of the character set) | Password generator |
| Fuel | Cost = distance ÷ efficiency × price per unit | Fuel cost |
The recurring mistake in this section is rounding down something you have to buy. Paint, concrete and fuel come in fixed sizes, so the useful output is the next pack size up, not the exact decimal. Each tool rounds its purchase guidance upward for that reason.
Coverage figures on a tin assume a smooth, sealed surface and often a single coat. A textured wall, a strong colour change or a first coat on bare plaster can use half as much again.
Three worked examples from this section
A $89.95 item at 25% off
Multiply by 0.75: 89.95 × 0.75 = $67.46, so the saving is $22.49. At the register the amount may be rounded to the nearest five cents, but the underlying calculation is unchanged.
Painting a 4 m by 3 m room with 2.4 m walls
Wall area is the perimeter times the height: 2 × (4 + 3) × 2.4 = 33.6 m². Two coats is 67.2 m². At 10 m² per litre that is 6.72 litres, so you buy 7 litres, and more if the ceiling is included.
- Wall area
- 33.6 m²
- Two coats
- 67.2 m²
- Paint at 10 m²/L
- 6.7 L
- Buy
- 7 L (or 2 × 4 L tins)
A 7-point GPA across three papers
Three credits at 7, three at 6 and six at 5 gives (21 + 18 + 30) ÷ 12 = 69 ÷ 12 = 5.75. Note that the six-credit paper carries twice the weight of each three-credit paper, which is exactly why a plain average of the three grades would be wrong.
A four-point scale is not a rescaled seven-point scale. Grade points are assigned by the institution, so convert with the official table rather than by dividing by 1.75.
The assumptions in everyday estimates
Everyday tools turn real-world quantities into rounded, shoppable numbers. They assume standard serving sizes, typical coverage rates, and prices you supply rather than live ones, so treat the output as a starting quantity to confirm at the till or the paint counter.
- Always round purchases up, not down: half a litre short is a second trip.
- Manufacturer coverage figures are usually for a single coat on a smooth, sealed surface, and rarely allow for texture or a strong colour change.
- Where a tool converts a recipe, it assumes level measures and does not correct for ingredient density unless it says so.
Reviewed 4 November 2026 · CalcFlow editorial
Common questions
Frequently asked
What if the weights do not add up to 100?+
They are normalised, so 30 and 70 behave the same as 15 and 35. The grade is still a share of the work completed — the remaining weight shows how much is outstanding.
What happens if the target is out of reach?+
The needed score comes back above 100%, which is shown as not reachable. Raising the score on any assessment still to come is the only lever left.
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