Worked examples · Updated 22 October 2026
How to calculate night shift allowance
Night shift allowance is a roster premium. It is not overtime, and it is not your whole salary. How night shift allowance is calculated comes down to one choice on the letter: a percent of daily CTC, or a fixed rupee amount per night. This page does the arithmetic in the open. The night shift allowance calculator uses the same two rules and keeps the figures on your phone.
Those links put the sample numbers in the address so the calculator can fill them. They are examples, not your salary. Do not share a link you edited with your own CTC.
The four steps
- Read the letter and pick one mode: a percent of daily CTC, or a fixed rupee amount per night.
- If it is a percent, daily CTC = annual CTC ÷ working days. Use 240 only when the letter does not define the day count.
- Per night = daily CTC × allowance percent. This month = per night × nights rostered.
- If it is a fixed amount, this month = that amount × nights rostered. Do not also apply a percent.
The “whole year” line in the calculator is this month × 12. It is not a tax-year forecast and it assumes every month looks like this one.
Example 1 — ₹12,00,000, 240 days, 15 nights
Daily CTC = 12,00,000 ÷ 240 = ₹5,000. The percent is the only thing that changes. These are illustration rates, not a company policy.
| Allowance % | Per night | 15 nights | If the month repeats × 12 |
|---|---|---|---|
| 20% | 5,000 × 0.20 = ₹1,000 | ₹15,000 | ₹1,80,000 |
| 25% | 5,000 × 0.25 = ₹1,250 | ₹18,750 | ₹2,25,000 |
| 30% | 5,000 × 0.30 = ₹1,500 | ₹22,500 | ₹2,70,000 |
People quote 20–30% as a software-company range. Twenty-five percent is the midpoint the calculator starts on. If your letter says 22%, type 22. Do not round yourself to 25% to look “standard.” There is no statutory night percent to round to.
Same CTC, fewer nights: 8 nights at 25% is 1,250 × 8 = ₹10,000. Same CTC, a heavier roster: 22 nights at 25% is 1,250 × 22 = ₹27,500. The percent did not change. The roster did.
Example 2 — why the day count matters
Annual CTC ₹18,00,000, allowance 25%, 12 nights. Two day counts:
| Working days | Daily CTC | Per night at 25% | 12 nights |
|---|---|---|---|
| 240 | 18,00,000 ÷ 240 = ₹7,500 | ₹1,875 | ₹22,500 |
| 260 | 18,00,000 ÷ 260 = ₹6,923.08 | ₹1,730.77 | ₹20,769.23 |
Using 240 when HR uses 260 overstates the night by about ₹1,731 this month. The calculator rounds each displayed line to the nearest rupee, so the 260-day case shows about ₹1,731 a night and ₹20,769 for the month. Match the day count to the policy, not to this default.
A monthly day count converts the same way. “22 working days a month” is about 22 × 12 = 264 days a year. Type 264 in the calculator. “26 days” is 312. Do not divide annual CTC by 30 just because the month has 30 dates. Night allowance policies that use daily CTC almost always mean working days, not calendar days.
Example 3 — fixed rupees, including a second rate
Some letters skip CTC entirely. If the slab is ₹800 a night and you worked 20 nights: 800 × 20 = ₹16,000. Open the calculator on Fixed ₹ / night, type 800 and 20, and you should see the same month total.
Weekend or “graveyard” slabs are a second line. Suppose weekdays are ₹800 (16 nights) and weekends are ₹1,200 (4 nights):
| Line | Working | Amount |
|---|---|---|
| Weekday nights | 800 × 16 | ₹12,800 |
| Weekend nights | 1,200 × 4 | ₹4,800 |
| This month | Add the two lines | ₹17,600 |
The free calculator holds one rate. Run it twice and add. Do not multiply ₹800 by 25% “to be safe.” That mixes the two modes and invents money the letter did not promise.
Example 4 — ₹8,00,000 at the low end of the range
Daily CTC = 8,00,000 ÷ 240 = ₹3,333.33. At 20% the night is ₹666.67. Twenty-two nights = ₹14,666.67, which the calculator rounds to ₹14,667. At 30% the same nights are ₹1,000 × 22 = ₹22,000 exactly, because 8,00,000 ÷ 240 × 0.30 = ₹1,000. The CTC did not change. The percent did. This is why copying a colleague’s night total is useless unless you also know their CTC, day count, percent, and roster.
What the payslip will still disagree about
- The allowance is already inside CTC, so the “extra” on this page is a component, not new cash.
- A shift counts only if it starts after a clock time written in the policy.
- Unpaid leave, a mid-month joining date, or an on-duty day removes nights.
- Payroll taxes the component, or takes PF or professional tax on it.
- The day count is 22 a month, 26, or something else you did not type.
When the page and the slip disagree, the slip and the policy PDF win. Use the examples to see whether a month is closer to ₹4,000 or ₹40,000 before you plan a SIP or a rent increase.
Where this stops
An hourly night rate — wage per hour, plus a differential on hours inside a night window — is a different sum. That is the hours and differential calculator, including shifts that cross midnight. A rotating roster with a general-shift premium and a night premium is the shift allowance calculator note. How Indian IT letters usually name the component is on night shift allowance in Indian IT companies. If you searched a company, the rate is still yours to read: TCS night shift allowance, Sagility night shift allowance.
Questions
How do you calculate night shift allowance from annual CTC?
Divide annual CTC by the working days in the policy (240 is only a default). That is daily CTC. Multiply by the allowance percent on the letter. Multiply again by the nights rostered this month.
What if the company pays a fixed amount per night?
Skip the percent. This month’s allowance is the rupee amount on the letter times the nights rostered. A weekend rate is a second line: calculate it separately and add.
Does 240 working days apply to every employer?
No. 240 is the default in this calculator, about 20 working days a month. If the letter uses 22 days a month, 26, or 260 a year, type that number. A higher day count lowers daily CTC and lowers the night amount.
Related
Illustrative arithmetic. Not HR advice. Author: Ramesh Choudhary.