Tools for the sums
nobody enjoys doing.
Every one runs in your browser. No account, nothing stored, nothing sent anywhere — and each one explains the formula underneath.
Stores & purchase
When to order, how much, and what it costs to hold it.
Costing & pricing
What an hour and a unit actually cost before you quote them.
Billing & tax
The arithmetic that has to be right on the invoice.
Documents
Fill it in, print it, done. Nothing is stored.
Materials
What the metal weighs before you quote it by the piece.
When you would reach for each of these
Each tool answers one question a manufacturer asks before a decision rather than after it. They are deliberately narrow — one set of inputs, one answer, no dashboard — because the moment you need them is usually the moment you have a supplier on the phone.
Before you place the order
Reorder level is the stock figure at which a fresh order has to go out, given how fast you consume the item and how long the supplier takes to deliver it. EOQ is how much to order at a time, balancing what it costs to raise an order against what it costs to hold the stock once it lands. Between them they answer when and how much, which is most of what a stores register is being asked for.
Before you send the quotation
Machine hour rate turns the cost of running a machine — depreciation, power, maintenance, the operator — into a per-hour figure you can quote against. Break-even tells you how many units have to leave the gate before the fixed costs are covered. Quoting without either is quoting from memory, and memory is generous about last year's power bill.
Before you raise the invoice
The GST calculator splits an amount into base and tax either way round, so an inclusive price and an exclusive one stop being two different arguments. The HSN code finder gets the classification right before it is printed rather than after, and the e-way bill checker settles whether a consignment needs one at all.
Before the material is priced
The metal weight calculator converts a size and a grade into a weight, which is what a raw-material or scrap quotation is actually priced on. Getting it wrong at this step is a margin error that survives every later correction.
Before you start typing numbers
- Do I need an account?
- No. Every tool on this page opens and runs without a sign-up, a trial or an email address.
- Is anything I type stored?
- No. The calculations run in your browser. The numbers are not sent to a server and nothing is kept once you close the tab.
- Which GST rate do the calculators use?
- You enter the rate that applies to your goods, so the tool works whatever slab you are on. The HSN code finder is there to help you identify the right classification in the first place.
- Can I use the generated invoice or challan for real work?
- They produce a document you can fill in and print today. For anything that has to be numbered in a series, tracked against an order and pulled back at filing time, those documents belong inside the ERP rather than in a one-off form.
- Why does a calculator stop being enough?
- Because a calculator answers with the numbers you happened to type. A reorder level is only useful while it is checked against real consumption, and a machine hour rate drifts the day power or maintenance costs change. Holding that arithmetic against live data, instead of asking you to re-enter it, is the job the system does.
If the answer you got here is one you will need again next month, that is the point at which a module inside the system is worth more than a form — it keeps the same arithmetic running against live stock, live costs and live orders.