# Annuant: FERS+CSRS Calculator — Federal annuity, TSP estimator

> Federal annuity, TSP estimator (iPhone/iPad app by 岚烜 吴.)

- Source: https://appshunter.io/ios/app/annuant-fers-plus-csrs-calculator/id6800396890 (this page in markdown: same URL + `.md`)
- Developer: [岚烜 吴](https://appshunter.io/developer/6788589687)
- Category: Finance, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 3 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2026-08-21
- Data updated: 2026-08-23
- User reviews in markdown: https://appshunter.io/ios/app/annuant-fers-plus-csrs-calculator/id6800396890/reviews.md

## What is Annuant?

Annuant computes your federal annuity the way OPM computes it.

Every formula in here cites a section of the CSRS/FERS Handbook. The tests use OPM's
own worked examples as their expected values, so when the Handbook works a case out
to $1,244 a month, that's what Annuant has to produce.

Four systems: FERS, CSRS, CSRS Offset, and CSRS/FERS transferees whose annuity comes
in two components.

Most of the real work is in the parts other calculators round off. High-3 is built
from your actual pay history, weighted by how long each rate was in effect, and it
looks across every three consecutive years rather than assuming your last three were
your best. Sick leave runs through OPM's 2,087-hour chart. Part-time service prorates
the money without touching your years of service. Military time gets the 3% deposit,
the date interest starts, and roughly how long the deposit takes to pay for itself.
Refunded and non-deduction periods often don't count, and the rules for which ones
are genuinely fiddly.

Tap any number and it opens into the formula, the values that went into it, and the
Handbook section behind it. If you think a figure is wrong, you can find out where it
came from.

Put two or three retirement dates side by side and compare what each is worth over a
lifetime, discounted to today's dollars. VERA, VSIP and RIF get their own panels.
When you're ready to talk to someone about it, export a three-page PDF with the
comparison table, the formulas and their citations, the assumptions you were running
on, and the rules involved. That file is built on your device.

One purchase, no subscription, no account. Your service history stays on your phone.

Annuant is not affiliated with OPM or the U.S. Government. Everything here is an
estimate for planning. The numbers that decide your retirement come from your agency
and from OPM.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Annuant Pro | $14.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-08-21

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-23.*