Contact
Calculator is built and operated by Delta Tech Solutions in Dar es Salaam, Tanzania. Email calculatorcotz@proton.me with a correction, a question or an idea for a new calculator — we aim to reply within a week.
Who runs this site
Calculator (calculator.co.tz) is built and operated by Delta Tech Solutions, a company based in Dar es Salaam, Tanzania.
The site is independent. It is not affiliated with the Tanzania Revenue Authority, NSSF, PSSSF, HESLB, WCF, EWURA, TANESCO, DAWASCO or any bank, telecom, lender or bureau de change whose rates appear in the calculators. Nobody pays to appear in a result, and no provider has any influence over what a calculator says.
Corrections come first
If a calculator or a guide is wrong, that matters more to us than anything else on this page. Send us:
- the page — a link, or the name of the calculator;
- the figure you believe is wrong, and what you think it should be;
- the source you are checking against: a TRA notice, an operator tariff sheet, an EWURA order, or whatever else the number actually comes from.
Tax bands, tariffs and exchange rates change, so if your source is newer than the date printed on the page, say so — we will update the figure and its date together. Every calculator that depends on a published rate says where that rate came from and when it was last checked, and we would rather correct it than defend it.
Suggestions for new calculators
Ideas for new tools are welcome. The most useful request names the inputs you would enter and the rule the answer should follow — for example, “a water bill from a meter reading, using the banded DAWASCO tariff”, or “import duty on a used vehicle”. If there is a published rate, table or formula behind the tool, point us at it. If there is not, we would rather tell you that than ship a calculator built on guessed numbers.
What we cannot help with
We cannot give personal financial, tax, legal or medical advice, and we cannot look anything up held by a third party. Your TRA assessment, your loan balance, a missing mobile-money transfer, a prepaid meter reading or a payslip query all sit with the institution concerned, and they are the only people who can resolve them. The calculators here estimate; they do not see your account.
Press, advertising and privacy
Journalists can find the site description, logo and suggested wording on the press page. Advertising and sponsorship enquiries go to the same address, as do privacy and data requests — our privacy policy sets out what the site collects and what it does not.
How to reach us, and when to expect a reply
Email is the only contact channel — there is no phone line or live chat, which keeps every exchange in writing:
Every message to that address is read. We aim to reply within a week, and a correction that affects a published figure comes first. We work in East Africa Time (UTC+3), so a reply will usually arrive during East African working hours.
Short notes are also fine on social media — we are @calculatorcotz on Instagram, TikTok and X. For anything about a figure we publish, email is better: it leaves a record we can check against the source.